REVIEW Download: 48| View: 29| Comments: 0 | doi:10.20944/preprints202001.0206.v1
Subject: Life Sciences, Biotechnology Keywords: adnectin; biosensor; Fibronectin; monobody; non-antibody scaffold; therapeutic
Online: 19 January 2020 (03:25:24 CET)
As a non-antibody scaffold, monobodies based on the fibronectin type III (FN3) domain overcome antibody size and complexity while maintaining analogous binding loops. However, antibodies and their derivatives remain the gold standard for design of new therapeutics. In response, clinical therapeutic proteins based on the FN3 domain are beginning to use native fibronectin function as a point of differentiation. The small and simple structure of monomeric monobodies confers increased tissue distribution and reduced half-life, whilst the absence of disulphide bonds improves stability in cytosolic environments. Where multi-specificity is challenging with an antibody format that is prone to mis-pairing of chains, FN3 domains in the fibronectin assembly already interact with a large number of molecules. As such, multiple monobodies engineered for interaction with therapeutic targets are being combined in a similar beads-on-a-string assembly which improves both efficacy and pharmacokinetics. Furthermore, full length fibronectin is able to fold into multiple conformations as part of its natural function and a greater understanding of how mechanical forces allow for the transition between states will lead to advanced applications that truly differentiate the FN3 domain as a therapeutic scaffold.
Tue, 24 December 2019
ARTICLE Download: 46| View: 57| Comments: 0 | doi:10.20944/preprints201912.0311.v1
Subject: Life Sciences, Biotechnology Keywords: adipose tissue; mesenchymal stem cells; regenerative medicine; lipocell; extracellular matrix preservation; ringer’s lactate; liposuction
Online: 24 December 2019 (07:53:44 CET)
This work aims to characterize a new method to recover low-manipulated human adipose tissue, enriched of adipose tissue-derived mesenchymal stem cells (ATD-MSCs) for autologous use in regenerative medicine applications. Lipoaspirated fat collected from patients was processed through Lipocell, a II-a medical device for dialysis of adipose tissue, by varying filter sizes and washing solutions. ATD-MSCs yield was measured with flow cytometry after SVF isolation in fresh and cultured samples. Purification from oil and blood was measured after centrifugation with spectrophotometer analysis. Extracellular matrix preservation was assessed through H&E staining and biochemical assay for total collagen, type-2 collagen, and GAGs quantification. Flow cytometry showed a 2-fold increase of ATD-MSCs yield in treated samples in comparison with untreated lipoaspirate; no differences where reported when varying filter size. The association of dialysis and washing thoroughly removed blood and oil from samples. Tissue architecture and extracellular matrix integrity were unaltered after Lipocell processing. Dialysis procedure associated with Ringer’s lactate preserves the proliferation ability of ATD-MSCs in cell culture. The characterization of the product shows that Lipocell is an efficient method to purify the tissue from undesired byproducts, preserving ATD-MSCs vitality and ECM integrity, resulting in a promising tool for regenerative medicine applications.
Thu, 28 November 2019
ARTICLE Download: 39| View: 55| Comments: 0
Subject: Life Sciences, Biotechnology Keywords: veterinary diagnostics; lateral flow tests; rapid tests; functionalized nanoparticles; signal enhancement; cow diseases
Online: 28 November 2019 (11:07:05 CET)
In this article, we describe an immunochromatographic test system developed for rapid serodiagnostics of cattle brucellosis using two markers: gold nanoparticles (GNPs) and quantum dots (QDs). The test system was compared with immunochromatographic serodiagnostics systems that use only one marker. The approbation of the test system was conducted on samples of cattle sera with low, but diagnostically significant titers of specific antibodies. We show that when two conjugates are used, the intensity of the detectable signal increases by 2–3 times compared with the test system using the QD conjugate and by more than 9 times compared with the system using the GNP conjugate.
SHORT NOTE Download: 24| View: 21| Comments: 0
Subject: Life Sciences, Biotechnology Keywords: boolean logic; nanopores; logic gates; electrolytic cell; NAND gate; NOR gate
Online: 28 November 2019 (09:55:40 CET)
An orthogonal pore ('orthopore') is conceptually based on an electrolytic cell with a standard pore (the main or 'longitudinal' pore) between cis and trans compartments filled with electrolyte and augmented by a secondary or 'transverse' pore in the form of a channel that is perpendicular to and intersects the main pore. Orthopores can be designed at different scales: macro through micro to nano. With nano-sized pores an analyte (polymer) can be threaded through the main pore and exposed at the junction to electrolyte flow through the secondary pore. Polymer translocation speeds are then independent of the current measured, which can be of an arbitrary magnitude even with the polymer stationary. Orthopores have a wide range of potential applications, including polymer (DNA and protein) sequencing, DNA unzipping, logic circuitry, and protein identification. The present report shows how orthopores can be used to implement boolean logic.
REVIEW Download: 69| View: 72| Comments: 0 | doi:10.20944/preprints201911.0351.v1
Subject: Life Sciences, Biotechnology Keywords: solid state fermentation; phenolic compounds; enzymes; polysaccharides
Online: 28 November 2019 (03:43:28 CET)
Solid state fermentation (SSF) is considered more sustainable than traditional fermentation because it uses low amounts of water and transforms agro-industrial residues into value added products. Enzymes, biofuels, nanoparticles and bioactive compounds can be obtained from SSF. The key factor in SSF processes is the choice of microorganisms and their substrates. Many fungal species can be used and are mainly used due their lower requirements of water, O2 and light. Residues rich in soluble and insoluble fiber are utilized by lignocellulolytic fungi because they have the enzymes that break fiber hard structure (lignases, celullases or hemicelullases). During the hydrolysis of lignin, some phenolic compounds are released but fungi also synthetize compounds such as mycophenolic acid, dicerandrol C, phenylacetates, anthraquinones, benzofurans and alkenyl phenols that have health beneficial effects such as antitumoral, antimicrobial, antioxidant and antiviral activities. Another important group of compounds synthetized by fungi during fermentation are polysaccharides that also have important health promoting properties. Fungal biofermentation has also proved to be a process which can release high contents of phenolics and it also increases the bioactivity of these compounds.
Thu, 21 November 2019
ARTICLE Download: 70| View: 87| Comments: 0 | doi:10.20944/preprints201911.0251.v1
Subject: Life Sciences, Biotechnology Keywords: endophyte; Trichoderma; fatty acid; antifeedant, myzus persicae; culture media
Online: 21 November 2019 (15:00:33 CET)
Increasing pesticide resistance in plant pathogens is major concern in agriculture production. Research on ecofriendly alternatives of chemical pesticides are more in demand in pesticide industry. In the current study, an ethyl acetate extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica). The bioactive components have been characterized following a bioassay-guided isolation against M. persicae. The chemical study of this bioactive extract resulted in the isolation of 1-oleoyl-2-linoleoyl-3-palmitoylglycerol (1), eburicol (2), (24R)-stigmast-4-ene-3-one or β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in compound 1 (oleic, linoleic and palmitic) showed strong dose-dependent aphid antifeedant effects against M. persicae. Liquid (PDB, and SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae with sorghum being the most active. Corn increased the content in linolenic, pearl millet the oleic and stearic and sorghum oleic and linolenic acids compared to rice. Their antifeedant effects correlated with linoleic /oleic acids. The phytotoxic effects of these extracts against Lolium perenne and Lactuca sativa varied with culture media, with sorghum being the least toxic.
Sun, 10 November 2019
ARTICLE Download: 65| View: 80| Comments: 0 | doi:10.20944/preprints201911.0100.v1
Online: 10 November 2019 (09:24:22 CET)
Paper recycling has increased in recent years. A principal consequence of this process is the problem of addressing polymeric components known as stickies. A deep characterization of stickies sampled over one year in a recycled paper industry in México was performed. Based on their chemical structure, an enzymatic assay was performed using lipases. Compounds found in stickies by Fourier-Transform Infrared spectrometry were poly (butyl-acrylate), dioctyl phthalate, poly (vinyl-acetate), and poly (vinyl-acrylate). Pulp with 4% consistency and pH=6.2 was sampled directly from the mill once macro stickies were removed. Stickies were quantified by counting the tacky macrostructures in the liquid fraction of the pulp using a Neubauer chamber before the paper was made, and they were analyzed with rhodamine dye and a UV lamp. Of the two enzymes evaluated, the best treatment condition used Lipase 30G at a concentration of 0.44 g/L, which produced a 35.59% decrease in stickies. SebOil DG showed a smaller stickies reduction of 21.5% when used at a concentration of 0.33 g/L. Stickies in kraft paper processes were actively controlled by the action of lipases, and future research should focus on how this enzyme recognizes its substrate and should apply synthetic biology to improve lipase specificity.
Sun, 3 November 2019
ARTICLE Download: 87| View: 107| Comments: 0 | doi:10.20944/preprints201911.0023.v1
Subject: Life Sciences, Biotechnology Keywords: monoclonal antibodies; Mabs; fusion; false positives; hapten immunoassays; competitive immunoassays; ELISA; antibody validation; antibody quality; microarray; hybridoma technology; linker recognition; high-throughput screening; HTS; heterology concept
Online: 3 November 2019 (17:00:59 CET)
The primary screening of hybridoma cells is a time-critical and laborious step during the development of monoclonal antibodies. Often critical errors occur in this phase, which supports the notion that the generation of monoclonal antibodies with hybridoma technology is difficult to control and hence a risky venture. We think that it is crucial to improve the screening process to eliminate most of the immanent deficits of the conventional approach. With this new microarray-based procedure, several advances could be achieved: Selectivity for excellent binders, high throughput, reproducible signals, avoidance of misleading avidity (multivalency) effects, and simultaneous performance of competition experiments. The latter can directly be used to select clones of desired cross-reactivity properties. In this paper, a model system with two excellent clones against carbamazepine, two weak clones and blank supernatant has been designed to examine the effectiveness of the new system. The excellent clones could be detected largely independent of the IgG concentration, which is unknown during the clone screening since the determination and subsequent adjustment of the antibody concentration is not possible in most cases. Furthermore, in this approach, the enrichment, isolation, and purification of IgG for characterization is not necessary. Raw cell culture supernatant can be used directly, even when fetal calf serum (FCS) or other complex media had been used. In addition, an improved method for the oriented antibody-immobilization on epoxy-silanized slides is presented. Based on the results of this model system, we conclude that this approach should be preferable to most other protocols leading to many of false positives, causing expensive and lengthy confirmation steps to weed out the poor clones.
Tue, 22 October 2019
REVIEW Download: 84| View: 80| Comments: 0 | doi:10.20944/preprints201910.0253.v1
Subject: Life Sciences, Biotechnology Keywords: tropical cash crops; coffee; cacao; papaya; chromosome engineering; synthetic biology
Online: 22 October 2019 (05:32:50 CEST)
Background Tropical and subtropical crops such as coffee, cacao, and papaya are valuable commodities and its consumption is a seemingly indispensable part of the daily lives of billions of people across the world. Conventional breeding in these crops is lengthy and yields are threatened by runaway global warming. In this review we propose the application of chromosome engineering and synthetic biology principles in order to enhance synthesis of key metabolites, and transmission of wild traits for resistance to stress and disease. Conclusions It is hoped that the adoption of such technological approaches may enhance the resilience of agricultural communities, lead to economic growth and secure the availability of key resources for generations to come.
Sun, 13 October 2019
ARTICLE Download: 82| View: 185| Comments: 0 | doi:10.20944/preprints201910.0147.v1
Subject: Life Sciences, Biotechnology Keywords: blackleg; brassica; diagnosis; effector; genome alignment; leptosphaeria biglobosa; leptosphaeria maculans; marker; PCR
Online: 13 October 2019 (16:08:55 CEST)
Background: Accurate diagnosis of the differentially aggressive fungus Leptosphaeria maculans and Leptosphaeria biglobosa causing Blackleg in crucifers is crucial. Available markers were designed decades ago which may become ineffective due to the ever evolving nature of the fungus, requiring the development of more precise molecular markers. Methods: The whole genomes of available isolates belonging to this two species were aligned using progressive MAUVE tool, species specific genomic regions were extracted and species specific primers were designed from the sequences that encode for effector proteins. Results: Three (Lm1, Lm2 and Lm5) and two (Lb3 and Lb3’) primer sets specifically detected the isolates of target species in PCR based assay, of which the primers Lm5 and Lb3’ were multiplexed for detection of Leptosphaeria maculans and Leptosphaeria biglobosa, generating PCR amplicons of 230 and 834 bp, respectively from a single PCR reaction. The markers were highly sensitive and were able to amplify target species from crude ‘pseudothecia and ascospores suspension’ without requiring DNA extraction. Conclusions: These markers, solitarily or in combination, designed from species specific genomic segments will serve as precise, sensitive and rapid detection of Leptosphaeria maculans and Leptosphaeria biglobosa species and will be helpful for surveillance, management and transboundary quarantine of the devastating disease.
Mon, 30 September 2019
ARTICLE Download: 50| View: 139| Comments: 0
Subject: Life Sciences, Biotechnology Keywords: chalcopyrite bioleaching; low temperature; microbial community; passivation; extracellular polymeric substances; ferric iron
Online: 30 September 2019 (07:56:59 CEST)
Low-temperature biohydrometallurgy is implicated in metal recovery in alpine mining area, but our knowledge on its mechanism has been limited. To this end, an Acidithiobacillus ferrivorans strain and a mixed culture were used for chalcopyrite bioleaching at 6 °C. The passivation of the mineral surface was analyzed using X-ray photoelectron spectroscopy (XPS), the microbial community structure of the mixed culture-mediated system was tested using high-throughput sequencing technology, and the extracellular polymeric substances (EPS) and ferric iron on the microbe-mineral interface were measured. A higher copper extraction rate was achieved using the mixed culture but it did not relieve the passivation of the mineral surface. Acidithiobacillus spp. and Sulfobacillus spp. were the two major lineages in the mixed culture-mediated system. In the fast-leaching stage, more EPS and ferric iron were extracted in the mixed culture-mediated system. In conclusion, Sulfobacillus spp. can relieve the inhibition of organic components to Acidithiobacillus spp., maintaining the robustness of the leaching system and more Fe(III) complexed by elevated EPS can enhance chalcopyrite bioleaching by the mixed culture.
ARTICLE Download: 121| View: 342| Comments: 0 | doi:10.20944/preprints201909.0340.v1
Subject: Life Sciences, Biotechnology Keywords: conjugation; solid media; saccharomyces cerevisiae; trans-kingdom; escherichia coli; pta-mob; yeast assembly
Online: 30 September 2019 (05:08:57 CEST)
Conjugation is a bacterial mechanism for DNA transfer from a donor cell to a wide range of recipients, including both prokaryotic and eukaryotic cells. In contrast to conventional DNA delivery techniques, such as electroporation and chemical transformation, conjugation eliminates the need for DNA extraction, thereby preventing DNA damage during isolation. While most established conjugation protocols allow for DNA transfer in liquid media or on a solid surface, we developed a procedure for conjugation within solid media. Such a protocol may expand conjugation as a tool for DNA transfer to species that require semi-solid or solid media for growth. Conjugation within solid media could also provide a more stable microenvironment in which the conjugative pilus can establish and maintain contact with recipient cells for the successful delivery of plasmid DNA. Furthermore, transfer in solid media may enhance the ability to transfer plasmids and chromosomes greater than 100 kbp. Using our optimized method, plasmids of varying sizes were tested for transfer from E. coli to S. cerevisiae. We demonstrated that there was no substantial decrease in conjugation frequency as plasmid size increased—up to 138.5 kbp in length. Finally, we established an efficient PCR-based synthesis protocol to generate custom conjugative plasmids
Tue, 17 September 2019
ARTICLE Download: 52| View: 125| Comments: 0 | doi:10.20944/preprints201909.0189.v1
Subject: Life Sciences, Biotechnology Keywords: miR-139-5p; SLC7A11; proliferation; migration; pancreatic cancer (PANC)
Online: 17 September 2019 (12:42:14 CEST)
Objective: Pancreatic carcinoma (PANC) is one of the important aggressive cancers, with deficiency in effective therapeutics. Studies have unveiled that miR-139-5p expression is significantly downregulated in other types of cancers. However, the functions and mechanisms of miR-139-5p in PANC remain unclear. Methods: Bioinformatic analysis was performed to analyze the differentially expressed genes in the TCGA database. PANC cell line with overexpressed miR-139-5p and Solute Carrier Family 7, Member 11 (SLC7A11) was established, and has been used to detect cell proliferation, migration, invasion and colony formation in PANC. Subsequently, bioinformatic analysis and luciferase assay were performed to confirm that SLC7A11 was a target gene of miR-139-5p. Xenograft mouse model was used to investigate the role of miR-139-5p in PANC tumorigenicity. Results: Through bioinformatic analysis, miR-139-5p was predicted to regulate phosphatidylinositol signaling pathway by targeting SLC7A11. MiR-139-5p was found to be lowly expressed in PANC tissues, while SLC7A11 was highly expressed. Low expression of miR-139-5p and high expression of SLC7A11 were positively associated with poor clinical outcomes. PANC cell proliferation, migration, and invasion could be inhibited by miR-139-5p overexpression and could be promoted by SLC7A11 overexpression. MiR-139-5p could regulate the protein expression level of PI3K and Akt associated with phosphatidylinositol signaling pathway could be by inhibiting the expression of SLC7A11. MiR-139-5p overexpression could suppress PANC tumor growth and the expression of SLC7A11, p-PI3K, p-Akt in tumor tissues. Therefore, the inhibiting effect of miR-139-5p to PANC cell proliferation, invasion and migration, at least, was partly due to its inhibiting effect on SLC7A11 expression. Conclusion: These results demonstrated a novel role of miR-139-5p/SLC7A11 in PANC and provided potential prognostic predictors for PANC patients.
Thu, 5 September 2019
ARTICLE Download: 152| View: 359| Comments: 2 | doi:10.20944/preprints201909.0055.v1
Subject: Life Sciences, Biotechnology Keywords: P-MFCs; Cynodon dactylon; energy; bioelectric potential; electricity generation
Online: 5 September 2019 (09:55:54 CEST)
In these times electricity is big trouble of problem facing by the world. Therefore, there is necessitating for the property basis of energy that is employed for as bio-electricity. Many of the scientists and researchers are trying to find out the sustainable energy generates with the help of plant microbial fuel cell. Plant microbial fuel cell (P-MFCs) could be feasibility technology approach of bio-electricity generation which is mutualism interaction of the plants along with their rhizospheric bacteria. In the present study, Plant-microbial fuel cell was observed in grass e-table evaluated in term of bioelectricity generation from Cynodon dactylon (Dooba Ghas). This e-table was connected with electrode and different condition (physical and chemical) to detect the change in bioelectric potential. It was found that maximum voltage generated among all the conditions was 4.24 ±2V at 15 days by using Cynodon dactylon through P-MFCs. The potential difference generated through P-MFCs was measured using a multimeter. The generation of bioelectricity was observed under different conditions like exposure to light and shade condition measured for voltage was found to be significantly different parameters. The maximum recorded under light and shade conditions were 3.82 ±2 V and 4.25 ±2 V respectively at 15 days of incubation.
Wed, 4 September 2019
REVIEW Download: 281| View: 259| Comments: 0 | doi:10.20944/preprints201909.0044.v1
Subject: Life Sciences, Biotechnology Keywords: Biosurfactants; Biotechnological applications; MEOR; synthetic surfactants; sustainability
Online: 4 September 2019 (13:32:06 CEST)
ABSTRACT Surfactants are a broad category of tensio-active biomolecules with multifunctional properties applications in diverse industrial sectors and processes. Surfactants are produced synthetically and biologically. The biologically derived surfactants (biosurfactants) are produced from microorganisms with Pseudomonas aeruginosa, Bacillus subtilis Candida albicans and Acinetobacter calcoaceticus as dominant species. Rhamnolipids, sophorolipids, mannosylerithritol lipids, surfactin, and emulsan are well known in terms of their biotechnological applications. Biosurfactants can compete with the synthetic surfactants in terms of performance with established advantages over the synthetic ones including eco-friendliness, biodegradability, low toxicity, and stability over a wide variability of environmental factors. However, at present, the synthetic surfactants are a preferred option in different industrial applications, because of their availability in commercial quantities, unlike the biosurfactants. Usage of synthetic surfactants introduce new species of recalcitrant pollutants to the environment and lead to undesired results where a wrong selection of surfactants is made. Substituting synthetic surfactants with biosurfactants resolves these drawbacks, thus, interest has been intensified in biosurfactant applications in a wide range of industries hitherto considered as experimental fields. This review, therefore, intends to offer an overview of diverse applications where biosurfactants have found useful, with emphases in petroleum biotechnology, environmental remediation and in the agriculture sector. Application of biosurfactant in these settings would lead to industrial growth and environmental sustainability.
Mon, 26 August 2019
ARTICLE Download: 35| View: 130| Comments: 0 | doi:10.20944/preprints201908.0270.v1
Subject: Life Sciences, Biotechnology Keywords: red plum apricot; fruit forest; planting area; benefits; soil water resources use limit by red plum apricot; suitable leaf amount of red plum apricot; sustainable produce of red plum apricot
Online: 26 August 2019 (15:24:14 CEST)
Red plum apricot is the best apricot over the world. Since having been introduced into Guyuan county in 1987 from Shaanxi province, red plum apricot grows well and then has been selected as good varieties to popularize in semirid loess hilly regions because the color of red plum apricot is beautiful, aroma fragrant , and taste is the mix of sour and sweet and nutrition is rich. Since 1995, the yield, benefits and planting area of red plum apricot increase doubly, and the distribution range of red plum apricot increased from Guyuan to the whole Ningxia, and then to Gansu province and so on in the water-limited regions, China. However, there are still some problems in the sustainable produce of red plum apricot. In order to promote the development of red plum apricot and meet people's increasing demand, we should do intensive study of the relationship between red plum apricot and environment and the comparison of possible methods to reduce the bad influence of drought, low temperature and frost on quality and production of red plum apricot, and determine the soil water resources use limit by red plum apricot and the suitable leaf amount of red plum apricot when the planting density equal soil water carrying capacity for red plum apricot and select the best method to reduce or evade the bad influence of soil drought, low temperature, frost and soil drought on red plum apricot to ensure the sustainable produce of red plum apricot in Sustainable Produce of red plum apricot in water-limited regions.
Mon, 5 August 2019
ARTICLE Download: 32| View: 94| Comments: 0
Subject: Life Sciences, Biotechnology Keywords: single cell oil; biomass; PUFA; docosahexaenoic acid (DHA); fish byproducts; biodiesel
Online: 5 August 2019 (04:13:54 CEST)
The following study reports on the first thraustochytrid isolates identified from Iceland. They were collected from three different locations off the northern coast of the country (Location A, Skagaströnd; Location B, Hveravík; and Location C, Eyjafjörður). Using 18S rDNA sequence analysis, isolates from Locations A and B were identified within the Thraustochytrium kinnei species while other isolates within the Sicyoidochytrium minutum species when compared to other known strains. Cells isolated from Locations A (2.10 ± 0.70 g/L) and B (1.54 ± 0.17 g/L) produced more biomass than the ones isolated from Location C (0.43 ± 0.02 g/L). This study offers the first-time examination of the utility of byproducts from fisheries as a nitrogen source in media formulation for thraustochytrids. Experiments showed that isolates produced more biomass (per unit of substrate) when cultured on nitrogen of marine (2.55 ± 0.74 g/L) as compared to of commercial origin (1.06 ± 0.57 g/L). Glycerol (2.43 ± 0.56 g/L) was a better carbon source than glucose (1.84 ± 0.57 g/L) in growth studies. Fatty acid (FA) profiles showed that the isolates from Location C (S. minutum) had low ratios of monounsaturated (4.21 ± 2.96%) and omega-6 (0.68 ± 0.59%) FAs. However, the isolates also had high ratios of docosahexaenoic acid (DHA; 35.65 ± 1.73%) and total omega-3 FAs (40.39 ± 2.39%), indicating that they could serve as a source of marine oils for human consumption and in aquaculture feeds. The T. kinnei isolates from Location A could be used in biodiesel production due to their high ratios of monounsaturated (18.38 ± 6.27%) long chain (57.43 ± 8.27%) FAs.
Fri, 26 July 2019
ARTICLE Download: 60| View: 115| Comments: 0 | doi:10.20944/preprints201907.0299.v1
Subject: Life Sciences, Biotechnology Keywords: VNNV; mass-immunization; sea bass; recombinant bacterins; spinycterins; DNA-damaged; repair-less
Online: 26 July 2019 (11:46:15 CEST)
This work describes practical immunization of European sea bass (Dicentrarchus labrax) juveniles against viral nervous necrosis virus (VNNV), a betanodavirus causing worldwide mortalities in many fish species. Protection was obtained with the so called spinycterin vehicles consisting in irreversibly DNA-damaged DNA-repair-less E.coli displaying at their surface a downsized antigen. In this work we, i) maximized bacterial expression levels by downsizing the C protein to a fragment (frgC91-220) containing most of its antigenicity, ii) developed an scalable autoinduction bacterial media based in soy-bean increasing membrane display and reproducibility, iii) enriched surface expression by screening different anchors from several prokaryotic origins (anchor+frgC91-220), iv) preserved frgC91-220 antigenicity by inactivating bacteria by irreversible DNA-damage by means of Ciprofloxacin, and v) increased safety using a repair-less E.coli strain as spinycterin chassis. These second generation of spinycterins protected fish against VNNV challenge with partial (Nmistic+frgC91-220) or 100 % (YBEL+frgC91-220 ) protection, in contrast to those fish immunized with frgC91-220 spinycterins. The proposed spinycterin platform has high levels of environmental safety and cost effectiveness, thus providing potential for small fish vaccines for sustainable aquaculture.
ARTICLE Download: 82| View: 105| Comments: 0 | doi:10.20944/preprints201907.0296.v1
Subject: Life Sciences, Biotechnology Keywords: point-of-care; cholesterol; clinical diagnostics; laboratory test
Online: 26 July 2019 (01:13:11 CEST)
Managing blood cholesterol levels is important for the treatment and prevention of diabetes, cardiovascular disease, and obesity. An easy-to-use, portable cholesterol blood test will accelerate more frequent testing by patients and at-risk populations. We aim to evaluate the performance of smartphone-based point-of-care cholesterol blood tests as compared to that of hospital-grade laboratory tests. We used smartphone systems that are already familiar to many people. Because smartphone systems can be carried around everywhere, blood can be measured easily and frequently. We compared the results of cholesterol tests with those of existing clinical diagnostic laboratory methods. We found that smartphone-based point-of-care lipid blood tests are as accurate as hospital-grade laboratory tests (N=116, R>0.97, P<0.001 for all 3 cholesterol blood tests: total cholesterol, high density lipoprotein, and triglyceride). Our system will be useful for those who need to manage blood cholesterol levels to motivate them to track and control their behavior.
Thu, 25 July 2019
ARTICLE Download: 89| View: 176| Comments: 0 | doi:10.20944/preprints201907.0290.v1
Subject: Life Sciences, Biotechnology Keywords: Irreversible electroporation, microfluidics, microelectrodes, pulsed electric field electroporation, intracellular metabolites, enzymes, quenching, E. coli, S. cerevisiae
Online: 25 July 2019 (11:44:33 CEST)
Exploring the dynamic behavior of cellular metabolism requires a standard laboratory method that guarantees rapid sampling and extraction of the cellular content. We propose a versatile sampling technique applicable to cells with different cell wall and cell membrane properties. The technique is based on irreversible electroporation with simultaneous quenching and extraction by using a microfluidic device. By application of electric pulses in the millisecond range, permanent lethal pores are formed in the cell membrane of Escherichia coli and Saccharomyces cerevisiae, facilitating the release of the cellular contents; here demonstrated by the measurement of glucose-6-phosphate and the activity of the enzyme glucose-6-phosphate dehydrogenase. The successful application of this device was demonstrated by pulsed electric field treatment in a flow-through configuration of the microfluidic chip in combination with sampling, inactivation, and extraction of the intracellular content in a few seconds. Minimum electric field strengths of 10 kV/cm for E. coli and 7.5 kV/cm for yeast S. cerevisiae were required for successful cell lysis. The results are discussed in the context of applications in industrial biotechnology, where metabolomics analyses are important.
Tue, 11 June 2019
ARTICLE Download: 99| View: 181| Comments: 0 | doi:10.20944/preprints201906.0091.v1
Subject: Life Sciences, Biotechnology Keywords: apoptosis; cyclosaplin; molecular docking; protein kinases; Sandalwood
Online: 11 June 2019 (09:45:07 CEST)
Natural products from plants such as, chemopreventive agents attract huge attention because of their low toxicity and high specificity. The rational drug design in combination with structure based modeling and rapid screening methods offer significant potential for identifying and developing lead anticancer molecules. Thus, the molecular docking method plays an important role in screening a large set of molecules based on their free binding energies and proposes structural hypotheses of how the molecules can inhibit the target. Several peptide based therapeutics have been developed to combat several health disorders including cancers, metabolic disorders, heart-related, and infectious diseases. Despite the discovery of hundreds of such therapeutic peptides however, only few peptide-based drugs have made it to the market. Moreover, until date the activities of cyclic peptides towards molecular targets such as protein kinases, proteases, and apoptosis related proteins have never been explored. In this study we explore the in silico kinase and protease inhibitor potentials of cyclosaplin as well as study the interactions of cyclosaplin with other cancer-related proteins. Previously, the structure of cyclosaplin was elucidated by molecular modeling associated with dynamics that was used in the current study. Docking studies showed strong affinity of cyclosaplin towards cancer-related proteins. The binding affinity closer to 10 indicated efficient binding. Cyclosaplin showed strong binding affinities towards protein kinases such as EGFR, VEGFR2, PKB and p38 indicating its potential role in protein kinase inhibition. Moreover, it displayed strong binding affinity to apoptosis related proteins and revealed the possible role of cyclosaplin in apoptotic cell death. The protein-ligand interactions using LigPlot displayed some similar interactions between cyclosaplin and peptide-based ligands especially in case of protein kinases and a few apoptosis related proteins. Thus, the in silico analyses gave an insight of cyclosaplin as a potential apoptosis inducer and protein kinase inhibitor.
Fri, 7 June 2019
ARTICLE Download: 60| View: 223| Comments: 0 | doi:10.20944/preprints201906.0063.v1
Subject: Life Sciences, Biotechnology Keywords: beta casein; MAC-T cells; Ile; milk protein synthesis; omics; proteomics
Online: 7 June 2019 (14:55:03 CEST)
The objective of this study was to determine the effects of supplementing L-isoleucine (L-Ile) on milk protein synthesis, using an immortalized bovine mammary epithelial (MAC-T) cell line. In this case, the cells were treated with 0, 0.3, 0.6, 0.9, 1.2 and 1.5 mM of supplemental Isoleucine (Ile), and the most efficient time for protein synthesis for each amino acid was determined by measuring the cell, medium and total protein at 0, 24, 48, 72 and 96 h. Confirmatory tests showed that 48h incubation time and 0.6 mM dosage of L-Ile are considered as the optimal time and dosage. The mechanism of milk protein synthesis was elucidated through proteomics analysis to clarify the metabolic pathway. When the L-Ile was supplemented, extracellular protein (medium protein) reached a peak at 48h, whereas in the case of the intracellular cell protein, it was shown to have reached to its peak at 24h in all L-Ile dosage treatments. In total, it is noted that there were 63 upregulated and 52 downregulated proteins. The results of the protein pathway analysis showed that the L-Ile group stimulated insulin/IGF pathway-mitogen activated protein kinase kinase/MAP kinase cascade, insulin/IGF pathway-protein kinase B signaling cascade, p53 pathway, de novo purine biosynthesis, Wnt signaling pathway, glycolysis, pentose phosphate pathway, and ATP synthesis which are pathways involved and related to protein and energy metabolism. Together, these results demonstrate that L-Ile supplementation was effective in stimulating β-casein synthesis by stimulating genes and pathways which are significantly related to protein and energy metabolism.
ARTICLE Download: 233| View: 338| Comments: 0 | doi:10.20944/preprints201906.0053.v1
Subject: Life Sciences, Biotechnology Keywords: Anammox; biofilms; granulation; methanogens; microbial ecology; sludge granules; wastewater
Online: 7 June 2019 (03:48:36 CEST)
As the global demand for water increases, so does the quantity of wastewater requiring treatment. Due to a relatively low carbon footprint, compared with conventional wastewater treatment technologies, anaerobic digestion (AD) was identified in the 1970s as a forerunner in the push for sustainability, when interest in sustainable technologies and renewable energy sources was first sparked. AD technology development ultimately resulted in the discovery of the ‘anaerobic granule’. It is a spontaneously-forming bio-aggregate of microbial cells capable of digesting pollutants and producing methane-rich biogas as a renewable source of bioenergy. The high settling velocity of such granules meant that AD systems could be operated as high-rate treatment processes, because the active, relatively-slow-growing, pollutant-removing biomass would be retained inside, and not washed out of, even bioreactors operated at extremely high volumetric loading rates. In the intervening years the emergence of the anaerobic ammonium oxidising (anammox) granule, aerobic granule, hydrogenic granule, oxygenic photogranule, and many other functionally-specialised granules, has opened new opportunities in wastewater treatment biotechnology. Whilst environmental engineering based around wastewater treatment is still a growing field of research and implementation, the granule (in all forms) is starting to catch the attention of microbial ecologists. It is a self-immobilised biofilm, with many of the properties of ‘conventional’ biofilms formed in Nature. However, as a single entity, a granule represents an entire community of microorganisms, competing or functioning cooperatively or in syntrophy. Together, inside a bioreactor, granules perform side-by-side arguably representing a meta-organism. Granules are gaining traction as the perfect samples for high-throughput studies on fundamental ecological concepts. Granular biofilms can be used to test hypotheses around drivers of diversity, community assembly, biofilm formation and maturation, community expansion and succession, community stress response, among others. This review outlines the history of three of the most influential types of granules: the anaerobic (methanogenic), aerobic and anammox granule. The main biochemical processes found in each type; their primary characteristics; and the typical makeup of the microbial community underpinning the processes are compared. Finally, the adoption of granules as the perfect ‘playground’ for experiments in microbial ecology is reviewed.
Mon, 20 May 2019
ARTICLE Download: 97| View: 187| Comments: 0 | doi:10.20944/preprints201905.0237.v1
Subject: Life Sciences, Biotechnology Keywords: Bacillus thuringiensis; cry gene; toxins; Coleoptera; Leptinotarsa decemlineata
Online: 20 May 2019 (10:05:23 CEST)
The genome of the Bacillus thuringiensis BM311.1 strain was sequenced and assembled in 359 contigs containing a total of 6,390,221 bp. The plasmidic ORF of a putative cry gene from this strain was identified as a potential novel Cry protein of 1138 amino acid residues with a 98% identity respect to Cry7Aa1 protein and a predicted molecular mass of 129.4 kDa. The primary structure of this Cry7Aa2 protein, which revealed the presence of eight conserved blocks and the classical structure of three domains, differed in 28 amino acid residues from that of Cry7Aa1. The cry7Aa2 gene was amplified by PCR and then expressed in the acrystalliferous strain BMB171. SDS-PAGE analysis confirmed the predicted molecular mass for the Cry7Aa2 protein and revealed that, after in vitro trypsin incubation, it was degraded to a toxin of 62 kDa. However, when treated with digestive fluids from Leptinotarsa decemlineata larvae two proteinase-resistant fragments of 60 and 65 kDa were produced. Spore and crystal mixture produced by the wild-type BM311.1 strain against L. decemlineata neonate larvae resulted in a LC50 (18.8 μg/ml), which was statistically equal to the estimated LC50 (20.8 μg/mL) for the recombinant BMB17-Cry7Aa2 strain. In addition, when this novel toxin was activated in vitro with commercial trypsin, the LC50 value was reduced 4 times approximately (LC50 = 4.9 μg/mL). The advantages of Cry7Aa2 protoxin compared to Cry7Aa1 protoxin when used in the control of insect pests are discussed.
Wed, 15 May 2019
ARTICLE Download: 174| View: 263| Comments: 0 | doi:10.20944/preprints201905.0183.v1
Subject: Life Sciences, Biotechnology Keywords: Anaerobic digestion; biogas; green energy; municipal solid waste; organic waste
Online: 15 May 2019 (10:33:58 CEST)
Global waste generation keeps increasing over the year and requires innovative solutions to minimize their impacts on environmental quality and public health. Predicted 2.2 billion tonnes per year of global municipal waste generation in the year 2025 which 1.6 fold is higher than in 2012. Hence, a strategic plan must be ascertained to overcome the future challenges of MSW locally and globally. Universiti Putra Malaysia (UPM) coined an initiative to demonstrate a showcase pilot plant for green energy production from MSW. Therefore, the data was obtained from the survey and actual sampling within the UPM compound to estimate the MSW generated and it's potentially used for green energy production. It is estimated that 5.0 – 7.0 tonne per day of MSW generated which about 30 - 35% is an organic fraction. Upon separation, the organic fractions were digested into biogas through anaerobic. At the maximum conversion of organic fraction, about 775 kWh of electricity may able to generate from the waste. In this study, the complete biorefinery setup and utilize organic components from the MSW generated in UPM was proposed that the biogas subsequently will be used to produce green energy in the form of electricity or cooking fuel.
Fri, 3 May 2019
ARTICLE Download: 82| View: 165| Comments: 0 | doi:10.20944/preprints201905.0005.v1
Subject: Life Sciences, Biotechnology Keywords: multicellular spheroids; 3D culture; gas-permeable plate; hydrogel beads; methylcellulose
Online: 3 May 2019 (14:20:44 CEST)
Culture systems for 3-dimensional tissues, such as multicellular spheroids, are indispensable for high-throughput screening of primary or patient-derived xenograft (PDX)-expanded cancer tissues. Oxygen supply to the center of such spheroids is particularly critical for maintaining cellular functions as well as avoiding the development of a necrotic core. In this study, we evaluated 2 methods to enhance oxygen supply: (1) using culture plate with gas-permeable polydimethylsiloxane (PDMS) membrane at its bottom and (2) embedding hydrogel beads in the spheroids. Culturing spheroids on PDMS increased cell growth and affected glucose/lactate metabolism and CYP3A4 mRNA expression and subsequent enzyme activity. The spheroids comprised 5000 Hep G2 cells and 5000 20 µm-diameter hydrogel beads did not develop a necrotic core for 9 days when cultured on a gas-permeable sheet. In contrast, central necrosis in spheroids lacking hydrogel beads was observed after day 3 of culture, even when using PDMS. These results indicate that the combination of gas-permeable culture equipment and embedded hydrogel beads improves culture 3D spheroids produced from primary or PDX-expanded tumor cells.
Sun, 28 April 2019
ARTICLE Download: 170| View: 320| Comments: 0 | doi:10.20944/preprints201904.0319.v1
Subject: Life Sciences, Biotechnology Keywords: Gymnema sylvestre; cell suspension cultures; copper oxide nanoparticles; gymnemic acid; phenolic compounds; pharmacological activity
Online: 28 April 2019 (12:09:11 CEST)
Gymnema sylvestre is a pharmacological plant which has a rich source of bioactive compounds specifically gymnemic acid (GA) and phenolic compounds (PC) that used for pharmaceutical industries. Sources for naturally occurring bioactive compounds are limited, due to geographical and seasonal variations; on the other hand, it is commercially in demand. Biosynthesis of G. sylvestre phytochemicals through in vitro culture often enhanced by elicitation. The use of cell suspension cultures (CSC) has interested serious attention on the production of essential phytochemicals. The current study is aimed at improving the contents of GA and PC in G. sylvestre CSC using the copper oxide nanoparticles (CuO NPs). Callus was obtained on MS medium with 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1 mg/L kinetin (KIN), phytoagar (8.0 g/L), and sucrose (30 g/L). The above medium devoid of agar was used for the initiation of CSC. The CSC was treated with three levels of CuO NPs (1, 3 or 5 mg/L) to enhance the production of GA and PC. The greatest amount of GA (89.25 mg/g dry cell mass, DCM), total phenolic (245.10 mg/g), and flavonoid (4.57 mg/g) in CSC were achieved when G. sylvestre cells were treated for 48 h with 3 mg/L CuO NPs. Also, the biomedical potential (antioxidant, antidiabetic, anti-inflammatory, antibacterial, antifungal and anticancer activities) were also high in the CuO NPs (3 mg/L) treated CSC extracts of G. sylvestre. CuO NPs elicitation of CSC significantly increased production of GA (9-fold), and PC than non-elicited CSC in G. sylvestre.
Mon, 1 April 2019
REVIEW Download: 114| View: 248| Comments: 0 | doi:10.20944/preprints201904.0023.v1
Online: 1 April 2019 (13:58:08 CEST)
Legumes are important sources of nitrogen and, therefore, the nitrogen fixing ability of the legume-rhizobia symbiosis has great potential to improve crop yields or reduce nitrogen fertilizer use. Unfortunately, legumes face serious and increasing threats of both biotic and abiotic stresses among which Fe-deficiency has been increased from past years. Fe nutrient deficiency limits pulse production and nitrogen fixation by specifically affecting any one of the four phases of legume-rhizobium symbiosis. Although Fe in soil is often present in adequate quantities, it is mainly present in insoluble Fe-(III) precipitates, limiting its uptake and utilization. The present review has focused on the iron nutrition and deficiency and probable uptake, transport and metabolism in legumes.
Fri, 1 March 2019
ARTICLE Download: 178| View: 210| Comments: 0 | doi:10.20944/preprints201903.0007.v1
Subject: Life Sciences, Biotechnology Keywords: Silybum marianum L.; Light regimes; Melatonin; Antioxidant; Phenolics; Flavonoids; Silymarin; Anti-inflammatory
Online: 1 March 2019 (12:20:03 CET)
Silybum marianum L. is a well-known medicinal herb, primarily used in liver protection. Light strongly affects several physiological processes along with secondary metabolites biosynthesis in plants. Herein, S. marianum was exploited for in vitro potential under different light regimes in the presence of melatonin. The optimum callogenic response occurred in combination of 1.0 mg/L α-naphthalene acetic acid and 0.5 mg/L 6-Benzylaminopurine under photoperiod. Continuous light associated with melatonin treatment increased total flavonoid content (TFC), total phenolic content (TPC) and antioxidant potential, followed by photoperiod and dark treatments. The increased level of melatonin has a synergistic effect on biomass accumulation under continuous light and photoperiod, while adverse effect was observed under dark condition. More detailed phytochemical analysis showed maximum total silymarin content (11.92 mg/g DW) when placed under continuous light + 1.0 mg/L melatonin. Individually, the level of silybins (A and B), silydianin, isolsilychristin and silychristin was found highest under continuous light. Anti-inflammatory activities were also studied and highest percent inhibition was recorded against 15-LOX for cultures cultivated under continuous light (42.33%). The current study helps to better understand the influence of melatonin and different light regimes on silymarin production as well as antioxidant and anti-inflammatory activities in S. marianum callus extracts.
Wed, 13 February 2019
ARTICLE Download: 174| View: 506| Comments: 0 | doi:10.20944/preprints201901.0031.v2
Subject: Life Sciences, Biotechnology Keywords: Chagalapoli (Ardisia compressa), fermented beverage, phenolic compounds
Online: 13 February 2019 (15:23:09 CET)
Chagalapoli fruit (Ardisia compressa) is similar to Vaccinium myrtillus (berries) with high-polyphenol content. The objective of this study was to evaluate the physicochemical properties of Chagalapoli fruit and to determine the conditions for the preparation of a fermented beverage using Saccharomyces cerevisiae yeast, evaluating the impact on sensory properties. The fermentation process lasted 4 days at 27 °C, with absence of light and a fixed pH of 3.8. The phenolic contents obtained in samples according to chromatograms were 1.27 mg(EPI)/mL in filtered juice, 1.59 mg(EPI)/mL in filtered fermented beverage, 1.91 mg(EPI)/mL in partially filtered juice and 3.19 mg(EPI)/mL in partially filtered fermented beverage. An affective test was carried out to determine the sensory acceptability of the final product, evaluating the flavor, color and aroma parameters. The fermented beverage with the greatest preference on color and flavor attributes was the partially filtered fermented beverage.
Tue, 29 January 2019
ARTICLE Download: 109| View: 357| Comments: 0 | doi:10.20944/preprints201901.0283.v1
Subject: Life Sciences, Biotechnology Keywords: breast cancer; cyclosaplin; 3D tumor model; peptide, sandalwood; silk
Online: 29 January 2019 (03:26:23 CET)
Development of novel anti-cancer peptides requires a rapid screening process which can be accelerated by using appropriate in vitro tumor models. Breast carcinoma tissue is a three dimensional (3D) microenvironment, which contains a hypoxic center surrounded by dense proliferative tissue. Biochemical clues provided by such 3D cell mass cannot be recapitulated in conventional 2D culture systems. In this experiment, we evaluate the efficacy of the sandalwood peptide, cyclosaplin on established in vitro 3D silk breast cancer model using invasive MDA-MB-231 cell line. The anti-proliferative effect of the peptide on 3D silk tumor model is monitored by alamar blue assay, with conventional 2D culture as control. The proliferation rate, glucose consumed, LDH, and MMP-9 activity of Human breast cancer cells are higher in 3D constructs compared to 2D. A higher concentration of drug is required to achieve 50% cell death in 3D culture than 2D cultures. The cyclosaplin treated MDA-MB-231 cells showed significant decrease in MMP-9 activity in 3D constructs. Microscopic analysis revealed the formation of cell clusters evenly distributed in the scaffolds. The drug treated cells were less in number, smaller and showed unusual morphology. Overall, these findings indicate the role of cyclosaplin as a promising anti-cancer therapeutics.
Fri, 11 January 2019
REVIEW Download: 158| View: 230| Comments: 0 | doi:10.20944/preprints201901.0115.v1
Subject: Life Sciences, Biotechnology Keywords: Motion; Inert; Mechanical stimulation; Sensory proteins
Online: 11 January 2019 (15:51:51 CET)
Thought runs through the mind like blood runs through our body to keep us alive. Like the mind, the body does not stay inert and is in constant motion. Not a single cell in our body is left inert unless cell is under stress or dying. These scenarios are reflected upon when a person is sick, the person lies in bed with less movement; however, is active when the person is healthy. The topic of mechanical stimulation has emerged due to the increasing understanding of the physical stimulations we face each day. Further understanding of the mechanically-regulated mechanism can help us explore the pathological events in a disease. Here, we reviewed the role of sensory proteins in pathological events that are observed in cardiomyopathy, cancer, respiratory, renal, obesity, genetics, physical injury and bacterial infection. Taken together, sensory proteins are mechanically-activated which assist reception of external physical stimulation and convert into biochemical to trigger intracellular signaling cascade.
Thu, 3 January 2019
ARTICLE Download: 232| View: 447| Comments: 0 | doi:10.20944/preprints201901.0022.v1
Online: 3 January 2019 (13:14:42 CET)
Advances in genetic engineering have placed synthetic biology at a prime position to develop new products, materials, and services that could contribute to the 2030 UN Sustainable Development goals. These include novel materials for water purification, new bio-based products to replace toxic industrial chemicals, and engineered organisms for bioremediation. Supporting the development of synthetic biology initiatives in developing countries is needed to ensure these benefits are open to all.
Mon, 17 December 2018
ARTICLE Download: 73| View: 151| Comments: 0 | doi:10.20944/preprints201812.0192.v1
Subject: Life Sciences, Biotechnology Keywords: hepatic injury; sealants; metalloproteinases; inflammatory response; wound healing
Online: 17 December 2018 (10:52:27 CET)
This study examines the matrix metalloproteinase (MMP) activity in the healing of liver injuries treated with biological adhesives Tachosil® and GelitaSpon® and the elastic cyanoacrylate Adhflex®. Hepatic lesions were induced in male rats using a Stiefel biopsy punch. Healing was assessed 2, 6, and 18 days after injury by quantifying tissue levels of MMP1, 2, 8, 9, and 13. Histopathological repair was evaluated using hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining and immunohistochemical markers CD31 and CD68. The sealants contributed to complete healing. Histopathology and MMP findings indicate that Adhflex® has slower degradation and a strong inflammatory reaction at the onset of healing. Early on, all MMPs showed higher levels in Adhflex® and Tachosil®-treated animals, and MMP2 and MMP9 expressions were significantly higher in the Adhflex-treated group at 18 days post-injury (T3). The Adhflex® group had significantly higher MMP8 and MPP13 levels than other treated groups and showed a sustained overexpression of all MMPs, even in the latest healing stages. Notably, the overexpression did not negatively influence the histological healing process. All hepatic trauma injuries should be treated as emergencies, and any easy-to-use and rapid sealant like Adhflex® could be considered as an option for treating liver trauma.
ARTICLE Download: 126| View: 132| Comments: 0 | doi:10.20944/preprints201812.0175.v1
Subject: Life Sciences, Biotechnology Keywords: Abies Alba Mill.; antioxidant activity; coniferous trees; essential oils; flavonoids; food preservation; green extraction; hydrodynamic cavitation; nutraceutics; polyphenols
Online: 17 December 2018 (07:07:56 CET)
Extracts from parts of coniferous trees have received increased interest due to their valuable bioactive compounds and properties, useful for plenty of experimental and consolidated applications, in fields comprising nutraceutics, cosmetics, pharmacology, food preservation, and stimulation of plant growth. However, the variability of the bioactive properties, the complexity of the extraction methods, and the use of potentially harmful synthetic chemicals, still represent an obstacle to the spreading of such valuable natural compounds. Hydrodynamic cavitation is emerging as a promising innovative technique for the extraction of precious food components and by-products from waste raw material of the agro-food production chain, which can improve processing efficiency, reduce resource consumption, and produce healthy, high-quality products. In this study, a process based on controlled hydrodynamic cavitation was applied for the first time to the production of aqueous solutions of silver fir (Abies Alba Mill.) needles with enhanced antioxidant activity. The observed levels of the in vitro antioxidant activity, comparable or higher than those found for reference substances, pure extracts, and other water extracts and beverages, highlight the very good potential of the HC process for the creation of solvent-free, aqueous solutions endowed with bioactive compounds extracted from silver fir needles.
Fri, 14 December 2018
REVIEW Download: 785| View: 459| Comments: 0 | doi:10.20944/preprints201812.0170.v1
Subject: Life Sciences, Biotechnology Keywords: bacterial nanocellulose; nanofibrillated nanocellulose; animal nanocellulose; algal nanocellulose; tissue engineering; tissue repair; wound dressing; cell delivery; drug delivery; antimicrobial properties
Online: 14 December 2018 (06:44:53 CET)
Nanocellulose is cellulose in the form of nanostructures, i.e. features not exceeding 100 nm at least in one dimension. These nanostructures include nanofibrils, e.g. in bacterial cellulose; nanofibers, e.g. in electrospun matrices; nanowhiskers and nanocrystals. These structures can be further assembled into bigger 2D and 3D nano-, micro- and macro-structures, such as nanoplatelets, membranes, films, microparticles and porous macroscopic matrices. There are four main sources of nanocellulose: bacteria (Gluonacetobacter), plants (trees, shrubs, herbs), algae (Cladophora) and animals (Tunicata). Nanocellulose has emerged for a wide range of industrial, technology and biomedical applications, e.g. for adsorption, ultrafiltration, packaging, conservation of historical artifacts, thermal insulation and fire retardation, energy extraction and storage, acoustics, sensorics, controlled drug delivery, and particularly for tissue engineering. Nanocellulose is promising for use in scaffolds for engineering of blood vessels, neural tissue, bone, cartilage, liver, adipose tissue, urethra and dura mater, for repairing connective tissue and congenital heart defects, and for constructing contact lenses and protective barriers. This review is focused on applications of nanocellulose in skin tissue engineering and wound healing as a scaffold for cell growth, for delivering cells into wounds, and as a material for advanced wound dressings coupled with drug delivery, transparency and sensorics. Potential cytotoxicity and immunogenicity of nanocellulose are also discussed.
Thu, 22 November 2018
ARTICLE Download: 65| View: 125| Comments: 0 | doi:10.20944/preprints201811.0533.v1
Subject: Life Sciences, Biotechnology Keywords: exercise classification; motion capture; virtual rehabilitation
Online: 22 November 2018 (04:33:58 CET)
The rapid development of algorithms for skeleton detection with relatively inexpensive contactless systems and cameras opens the possibility of virtual exercise therapy for patients with different complications. However, evaluation and confirmation of posture classifications is still needed. The purpose of this study was therefore to find the most accurate algorithm for automatic classification of human exercise movement. A Kinect V2 with 25 joints identification was used to record movements for data analysis. A total of 10 subjects volunteered for this study. Four algorithms were tested for the classification of different postures in Matlab. These were based on: total error of vector lengths, total error of angles, multiplication of these two parameters and simultaneous analysis of the first and second parameters. A base of 13 exercises was then created to test the recognition of postures by the algorithm, and to analyse subject performance. The best results for posture classification was shown by the second algorithm with an accuracy of 94.9%. The average correctness of exercises among the 10 participants was 94.2% (SD1.8%). The algorithms tested in this study therefore proved to be effective and could potentially form the basis for developing a system for remote monitoring of rehabilitation involving exercise.
Fri, 16 November 2018
ARTICLE Download: 128| View: 133| Comments: 0 | doi:10.20944/preprints201811.0385.v1
Subject: Life Sciences, Biotechnology Keywords: flux balance analysis; Saccharomyces cerevisiae; tequila; fermentation; higher alcohols
Online: 16 November 2018 (07:37:14 CET)
In this study is developed an aerobic and anaerobic stoichiometric model for Saccharomyces cerevisiae, compartmentalized in mitochondria and cytosol. This model considers the central metabolism of S. cerevisiae and it possesses the peculiarity of having catabolic and anabolic biochemical reactions for the synthesis of the higher alcohols contained in tequila; involving 94 metabolites and 117 reactions; of which 93 correspond to biochemical internal reactions and 24 to transport fluxes between the medium and the cell. The model is validated under aerobic and anaerobic conditions for the main fermentation metabolites and it coincides with experimental results and those in silico reported in the literature. This model is used to obtain three different physiological states of S. cerevisiae through of estimation of its distributions of fluxes calculated from experimental data reported in literature of fermentation in continuous culture during the tequila production under different dilution rate (0.04-0.12 h-1). The model developed constitutes a tool for the estimation of flux distribution maps during fermentation processes for the production of tequila, which could permit estimate yields and visualize different fermentation scenarios.
Tue, 13 November 2018
ARTICLE Download: 113| View: 209| Comments: 0 | doi:10.20944/preprints201811.0297.v1
Subject: Life Sciences, Biotechnology Keywords: genome engineering; synthetic biology; yeasts; Metschnikowia; genetic tools; DNA delivery; CUG-Ser
Online: 13 November 2018 (05:17:45 CET)
Yeasts belonging to the Metschnikowia genus are particularly interesting for the unusual formation of only two needle-shaped ascospores during their mating cycle. Presently, the meiotic process that can lead to only two spores from a diploid zygote is poorly understood. The expression of fluorescent nuclear proteins should allow the meiotic process to be visualized in vivo; however, no large-spored species of Metschnikowia has ever been transformed. Accordingly, we aimed to develop a transformation method for Metschnikowia borealis, a particularly large-spored species of Metschnikowia, with the goal of enabling the genetic manipulations required to study biological processes in detail. Genetic analyses confirmed that M. borealis, and many other Metchnikowiacea, are CUG-Ser yeasts. Codon-optimized selectable markers lacking CUG codons were used to successfully transform M. borealis by electroporation and lithium acetate, and transformants appeared to be the result of random integration. Mating experiments confirmed that transformed-strains were capable of generating large asci and undergoing recombination. Finally, random integration was used to transform an additional 18 yeast strains, and all attempts successfully generated transformants. The results provide a simple method to transform many yeasts from an array of different clades and can be used to study or develop many species for various applications.
Wed, 7 November 2018
REVIEW Download: 95| View: 65| Comments: 0 | doi:10.20944/preprints201811.0166.v1
Subject: Life Sciences, Biotechnology Keywords: Biodegradation, thermophiles, petroleum hydrocarbons, aliphatics, aromatics, metabolites
Online: 7 November 2018 (14:34:42 CET)
Contamination of the environment by petroleum products is a growing concern worldwide, and strategies to remove these contaminants have been evaluated. One of these strategies is biodegradation, which consists of the use of microorganisms. Biodegradation is significantly improved by increasing the temperature of the milieu, thus, the use of thermophiles, microbes that thrive in high-temperature environments, will render this process more efficient. For instance, various thermophilic enzymes have been used in industrial biotechnology because of their unique catalytic properties. Biodegradation has been extensively studied in the context of mesophilic microbes, and the mechanisms of biodegradation of aliphatic and aromatic petroleum hydrocarbons have been elucidated. However, in comparison, little work has been carried out on the biodegradation of petroleum hydrocarbons by thermophiles. In this paper, a detailed review of the degradation of petroleum hydrocarbons (both aliphatic and aromatic) by thermophiles has been carried out. This work has identified the characteristics of thermophiles, and unravelled specific catabolic pathways of petroleum products that are only found in thermophiles. Gaps that limit our understanding of the activity of these microbes have also been highlighted, and finally, different strategies that can be used to improve the efficiency of degradation of petroleum hydrocarbons by thermophiles have been proposed.
Tue, 6 November 2018
ARTICLE Download: 103| View: 133| Comments: 0 | doi:10.20944/preprints201811.0135.v1
Subject: Life Sciences, Biotechnology Keywords: iron oxide nanoparticles; multimodal nanoparticles; biodistribution; magnetic resonance imaging; aging; coating degradation
Online: 6 November 2018 (10:37:57 CET)
Medical imaging is an active field of research that fosters the necessity for novel multimodal imaging probes. In this line, nanoparticle-based contrast agents are of special interest, since those can host functional entities either within their interior, reducing potential toxic effects of the imaging tracers, and on their surface, providing high payloads of probes, due to their large surface-to-volume ratio. The long-term stability of the particles in solution is an aspect usually under-tackled during probe design in research laboratories, since their performance is generally tested briefly after synthesis. This may jeopardize a later translation into practical medical devices, due to stability reasons. To dig into the effects of nanoparticle aging in solution, respect to their behavior in vivo, iron oxide stealth nanoparticles were used at two stages (3 weeks vs. 9 months in solution), analyzing their biodistribution in mice. Both sets of nanoprobes showed similar sizes, zeta potentials and morphology, as observed by DLS and TEM but, fresh nanoparticles accumulated in the kidneys after systemic administration, while aged ones accumulated in liver and spleen, confirming an enormous effect of particle aging on their in vivo behavior, despite barely noticeable changes perceived on a simple inspection of their structural integrity.
Mon, 22 October 2018
REVIEW Download: 103| View: 59| Comments: 0 | doi:10.20944/preprints201810.0204.v2
Subject: Life Sciences, Biotechnology Keywords: DNA origami; aptamer; DNA nanotechnology; protein nano array; biosensor; logic gate; enzyme cascade; drug delivery system; targeted therapy; molecular robotics
Online: 22 October 2018 (10:57:21 CEST)
DNA origami has emerged in recent years as a powerful technique for designing and building 2D and 3D nanostructures. While the breadth of structures that have been produced is impressive, one of the remaining challenges, especially for DNA origami structures intended to carry out useful biomedical tasks in vivo, is to endow them with the ability to detect and respond to molecules of interest. Target molecules may be disease indicators or cell surface receptors, and the responses may include conformational changes leading to release of therapeutically relevant cargo. Nucleic acid aptamers are ideally suited to this task and are beginning to be used in DNA origami designs. In this review we consider examples of uses of DNA aptamers in DNA origami structures and summarise what is currently understood regarding aptamer-origami integration. We review three major roles for aptamers in such applications: protein immobilisation, triggering of structural transformation, and cell targeting. Finally, we consider future perspectives for DNA aptamer integration with DNA origami.
Fri, 19 October 2018
ARTICLE Download: 279| View: 206| Comments: 0 | doi:10.20944/preprints201810.0449.v1
Subject: Life Sciences, Biotechnology Keywords: green algae; biomass; fatty acids; Tetraselmis straiata; lipids; carotenoids; raceway ponds
Online: 19 October 2018 (11:09:56 CEST)
In the process of modernization and development, a human being always needed energy, which increased the dependency on the available sources of fossil fuel. Tetraselmis, a green algal genus belong to the order Chlorodendrales, are described by their strong green coloured chloroplast, flagellated cell bodies, and the occurrence of a pyrenoid within the chloroplast. In this study, four different strains of Tetraselmis species were successfully isolated from the saltpans Kovelong, Chennai, Tamil Nadu, India. The isolated strains were cultured in the normal basal medium and their morphological features were subsequently studied. The species of Tetraselmis straiata (T. straiata) Butcher BBRR1 was confirmed using molecular identification of 18S rRNA gene analysis and its observed systematic position. Among the four different isolates, T. straiata Butcher BBRR1 recorded a highest biomass concentration of 0.58 ± 0.021 g L-1, 15% lipids, 19% proteins and 17% carbohydrates when it grown under laboratory condition. Whereas, in open raceway ponds, T. straiata BBRR1 produced 0.95 ± 0.06 g L-1 biomass, 19% lipids, 28% proteins and 21% carbohydrates in an modified CFTRI I medium. The fatty acids profile of T. straiata Butcher BBRR1showed the presence of 33.14 % Palmitic acid, 22.64% 11- Octadecenoic acid and 21.94% Heptadecanoic acid. Since T. straiata BBRR1 can be cultivated in open ponds without a major contaminations, this species can be used as novel biomass feedstock to produce biofuels. This study may suggest the potential of T. straiata BBRR1 for biofuel production and could compete the energy demand in the future. In addition, this species contains healthful components of carotenoids, lipids and proteins, all these may provide a health benefits beyond basic nutrition.
Wed, 17 October 2018
ARTICLE Download: 214| View: 146| Comments: 0 | doi:10.20944/preprints201810.0374.v1
Subject: Life Sciences, Biotechnology Keywords: mini-bioreactors; parallelization; automation; digitalization; multivariate analysis; dynamic processes
Online: 17 October 2018 (06:19:46 CEST)
Mini-bioreactor systems enabling automatized operation of numerous parallel cultivations have been used to accelerate and optimize bioprocess development. As implementation of fed-batch conditions, multiple options of process control and sample analysis are possible, these systems represent valuable screening tools for large-scale production. However, the dynamic behavior of cultivations has not yet been considered regarding data evaluation and decision making during high-throughput screening in mini-bioreactors. In this study, the characterization of Saccharomyces cerevisiae AH22 secreting recombinant endopolygalacturonase is performed in 48 parallel fed-batch cultivations regarding 16 experimental conditions. Automated parallel process control, frequent sampling and analysis were implemented. Data-driven multivariate methods were developed to allow for fast, automated decision making as well as online predictive data analysis regarding endopolygalacturonase production. Using dynamic process information, a cultivation with abnormal behavior could be detected by principal component analysis as well as two clusters of similarly behaving cultivations, later classified according to the feeding rate. By decision tree analysis, cultivation conditions leading to an optimal recombinant product formation could be identified automatically. The developed method is easily adaptable and suitable for automatized process development reducing the experimental times and costs.
Tue, 16 October 2018
REVIEW Download: 115| View: 92| Comments: 0 | doi:10.20944/preprints201810.0334.v1
Online: 16 October 2018 (05:02:00 CEST)
Schistosomiasis, a disease historically associated with poverty, lack of sanitation and social inequalities, is a chronic, debilitating parasitic infection, affecting hundreds of millions of people in endemic countries. Although schistosomiasis control approach has shown that chemotherapy is capable of reducing morbidity in humans, rapid re-infection is a reminder that the impact of drug treatment on transmission control or elimination initiatives is marginal. In addition, and regardless of more than two decades of well-executed control activities based on large-scale chemotherapy, the disease is expanding in many areas including Brazil. The development of the Sm14/GLA-SE schistosomiasis vaccine is an emblematic open knowledge innovation that has successfully completed Phase I and Phase IIa clinical trials, with Phase II/III trials underway in the African continent and to be followed in Brazil. Discovery and experimental phases were long term achievements leading to a robust collection of data that are strongly supporting the presently ongoing Clinical Phase. This paper reviews the development of the Sm14 vaccine formulated with GLA-SE (Glucopyranosyl Lipid A), from the earlier experimental developments to clinical trials including the recent status of Phase II studies.
Mon, 15 October 2018
ARTICLE Download: 291| View: 342| Comments: 0 | doi:10.20944/preprints201807.0287.v2
Subject: Life Sciences, Biotechnology Keywords: PCR; recombination; cloning; engineering; biotechnology; synthetic biology; synthetic nucleotide; plasmids; repository; minimalism; Escherichia coli; mutagenesis
Online: 15 October 2018 (09:22:22 CEST)
Minimal plasmids play an essential role in many intermediate steps in molecular biology. They can for example be used to assemble building blocks in synthetic biology or be used as intermediate cloning plasmids that are ideal for PCR-based mutagenesis methods. A small backbone also opens up for additional unique restriction enzyme cloning sites. Here we describe the generation of pICOz, a 1185 bp fully functional high-copy cloning plasmid with an extended multiple cloning site (MCS). To our knowledge, this is the smallest high-copy cloning vector ever described.
Wed, 10 October 2018
REVIEW Download: 192| View: 253| Comments: 0 | doi:10.20944/preprints201810.0204.v1
Subject: Life Sciences, Biotechnology Keywords: DNA origami; aptamer; DNA nanotechnology; protein nano array; biosensor; logic gate; enzyme cascade; drug delivery system; targeted therapy; molecular robotics
Online: 10 October 2018 (05:47:26 CEST)
DNA origami has emerged in recent years as a powerful technique for designing and building 2D and 3D nanostructures. While the breadth of structures that have been produced is impressive, one of the remaining challenges, especially for DNA origami structures intended to carry out useful biomedical tasks in vivo, is to endow them with the ability to detect and respond to molecules of interest. Target molecules may be disease indicators or cell surface receptors, and the responses may include conformational changes leading to release of therapeutically relevant cargo. Nucleic acid aptamers are ideally suited to this task and are beginning to be used in DNA origami designs. In this review we consider examples of uses of DNA aptamers in DNA origami structures and summarise what is currently understood regarding aptamer-origami integration. We review three major roles for aptamers in such applications: protein immobilisation, triggering of structural transformation, and cell targeting. Finally, we consider future perspectives for DNA aptamer integration with DNA origami.
Wed, 3 October 2018
ARTICLE Download: 141| View: 148| Comments: 0 | doi:10.20944/preprints201810.0066.v1
Subject: Life Sciences, Biotechnology Keywords: nucleotide triphosphate, label-free, K-Ras, apyrase, terbium
Online: 3 October 2018 (17:32:44 CEST)
A new label-free molecular probe for luminescent nucleotide detection in neutral aqueous solution is presented. Phosphate-containing molecules such as nucleotides possess vital role in cell metabolism, energy economy, and signaling. Thus the monitoring of nucleotide concentration and nucleotide related enzymatic reactions is of high importance. Two component lanthanide complex formed from Tb(III) ion carrier and light harvesting antenna, readily distinguishes nucleotides containing different number of phosphates and enable direct detection of enzymatic reactions converting nucleotide triphosphate (NTP) to nucleotide di/monophosphate or the opposite. Developed sensor enables the detection of enzymatic activity with a low nanomolar sensitivity, as highlighted with K-Ras and apyrase enzymes in there hydrolysis assays performed in high throughput screening compatible 384-well plate format.
ARTICLE Download: 139| View: 111| Comments: 0 | doi:10.20944/preprints201810.0046.v1
Subject: Life Sciences, Biotechnology Keywords: Bio-disinfection, G. latifolium, Water, Z. zanthoxyloides.
Online: 3 October 2018 (12:53:16 CEST)
Water and sanitation facilities in sub-Saharan Africa and Africa in general are appalling and for the most part absent. Progress continues with respect to the development of plant materials as potent adsorbents, disinfectants, coagulants, flocculants, wetland species and lots more as substitutes for the dangerous chemical disinfectants. This research presents the potential of phyto-active components of Zanthoxylum zanthoxyloides and Gongronema latifolium as effective biocides against water microbial contaminants. Dry powder of Zanthoxylum zanthoxyloides and Gongronema latifolium were extracted and prepared into different concentrations with ethyl acetate and chloroform, ranging from 25 to 500 mg/ml. These fractions were then examined for antimicrobial activities against inherent bacterial and fungal water contaminants using disc diffusion assay. Fractions were afterwards screened for phytochemical active compounds using standard methods. Crude extracts of the different plant examined selectively comprise saponins, tannins, reducing sugars, anthraquinones, flavonoids, terpenoids, phlobatanins and alkaloids. All plant extracts showed broad spectrum antibiosis against selected gram positive and gram negative bacteria including E. coli, P. aeruginosa, Klebsiella sp, S. pneumoniae and B. cereus, as well as tested fungi, including A. niger, A. flavus, Trichoderma sp and Candida sp. While all extracts exhibited maximum antibiosis at 500 mg/ml, the chloroform extracts compared well than ethyl acetate extracts. The overall results revealed that antimicrobial activities of the plant extracts are dose dependent with comparative activity greater than that of commercial antibiotics at the concentration of extracts tested. E.coli was the most susceptible microbial isolate tested and represents the potential of the extract against a group of coliform which are important indicators of microbial pollution in water. Other microbial isolates also recorded sensitivity to extracts tested at varying degrees. The findings indicate that microbes tested were mostly susceptible to chloroform extract of Z. zanthoxyloides and G. latifolium except for the activity of ethyl acetate extract of Z. zanthoxyloide against E.coli. Results of phytochemical screening of the extract also showed the varied presence of alkaloids, saponins, tannins, flavonoids, terpenoids and anthraquinones The results indicated that plant materials investigated can be developed as effective biocides against water microbial contaminants
Thu, 27 September 2018
ARTICLE Download: 137| View: 163| Comments: 0 | doi:10.20944/preprints201809.0529.v1
Subject: Life Sciences, Biotechnology Keywords: hemodialysis; end stage renal disease; diabetes; motor performance; gait; balance; wearable; aging; frailty; diabetic peripheral neuropathy
Online: 27 September 2018 (04:19:43 CEST)
Motor functions are deteriorated by aging. Some conditions may magnify this deterioration. To examine whether hemodialysis (HD) process would negatively impact gait and balance beyond diabetes condition among mid-age adults (48-64 years) and older adults (65+ years). One hundred and ninety-six subjects (age=66.2±9.1 years, body-mass-index=30.1±6.4 kg/m2, female=56%) in 5 groups were recruited: mid-age adults with diabetes undergoing HD (Mid-age HD+, n=38) and without HD (Mid-age HD-, n=40); older adults with diabetes undergoing HD (Older HD+, n=36) and without HD (Older HD-, n=37); and non-diabetic older adults (Older DM-, n=45). Gait parameters (stride velocity, stride length, gait cycle time, and double support) and balance parameters (ankle, hip, and center of mass sways) were quantified using validated wearable platforms. Groups with diabetes had overall poorer gait and balance compared to the non-diabetic group (p<0.050). Among people with diabetes, the HD+ had significantly worsened gait and balance when comparing to the HD- (Cohen’s effect size d=0.63-2.32, p<0.050). Between-group difference was more pronounced among older adults with the largest effect size observed for stride length (d=2.32, p<0.001). Results suggested that deterioration in gait speed among the HD+ was correlated with age (r=-0.440, p<0.001), while this correlation was diminished among the HD-. Interestingly, results also suggested that poor gait in the Older HD- related to poor balance, while no correlation was observed between poor balance and poor gait among the Older HD+. Using objective assessments, results confirmed that the presence of diabetes can deteriorate gait and balance, and this deterioration can be magnified by HD process. Among non-HD people with diabetes, poor static balance described poor gait. However, among people with diabetes undergoing HD, age was a dominate factor describing poor gait irrespective of static balance. Results also suggested feasibility of using wearable platforms to quantify motor performance during routine dialysis clinic visits. These objective assessments may assist in identifying early deterioration in motor function, which in turn may promote timely intervention.
Mon, 24 September 2018
ARTICLE Download: 148| View: 149| Comments: 0 | doi:10.20944/preprints201809.0452.v1
Subject: Life Sciences, Biotechnology Keywords: Microbial fuel cell; polymer matrix; immobilization of bacterial cells; interaction of cell membranes with carbon nanotubes, boostconverter accumulation
Online: 24 September 2018 (11:06:23 CEST)
The anode of a microbial fuel cell (MFC) was formed on a graphite electrode and immobilized Gluconobacter oxydans VKM-1280 bacterial cells. Immobilization was performed in chitosan, poly(vinyl alcohol) or N-vinylpyrrolidone-modified poly(vinyl alcohol). Ethanol was used as substrate. The anode was modified using multiwalled carbon nanotubes. The aim of the modification was to create a conductive network between cell lipid membranes, containing exposed PQQ-dependent alcoholdehydrogenases, and the electrode to facilitate electron transfer in the system. The bioelectrochemical characteristics of modified anodes at various cell/polymer ratios were assessed via current density, power density, polarization curves and impedance spectres. MFCs based on chitosan at a matrix/cell volume ratio of 5:1 produced maximal power characteristics of the system (8.3 μW/cm2) at a minimal resistance (1111 Ohm cm2). Modification of the anode by multiwalled carbon nanotubes led to a slight decrease of internal resistance (down to 1078 Ohm cm2) and to an increase of generated power density up to 10.6 μW/cm2. We explored the possibility of accumulating electric energy from an MFC on a 6,800-μF capacitor via a boost converter. Generated voltage was increased from 0.3 V up to 3.2 V. Accumulated energy was used to power a Clark-type biosensor and a bluetooth transmitter with three sensors, a miniature electric motor and a light-emitting diode.
Thu, 20 September 2018
ARTICLE Download: 152| View: 180| Comments: 0 | doi:10.20944/preprints201809.0419.v1
Subject: Life Sciences, Biotechnology Keywords: Lignocellulosic biomass; cellulose; hemicellulose; lignin; biofuel
Online: 20 September 2018 (16:16:47 CEST)
Carbohydrate composition of lignocellulosic biomass is one of the main factors for production of biofuel from the plant biomass. Various methods like Thermogravimetric analysis (TGA), near infrared spectroscopy (NIR) often used in determination of polysaccharide component of the plant biomass. However, used of such tools is based on the prediction and very costly. This paper discussed about the determination of carbohydrate composition (cellulose, hemicellulose and lignin) using the automatic fibre estimation system. The protocol was developed for the estimation of cellulose, hemicellulose and lignin component of lignocellulosic biomass. This protocol explains a simple method to estimate the polysaccharide component of lignocellulosic biomass. This protocol can be used not only lignocellulosic biomass but also for other hardwood biomass. The advantages and techniques, procedures are presented below.
Mon, 17 September 2018
ARTICLE Download: 233| View: 130| Comments: 0 | doi:10.20944/preprints201809.0298.v1
Subject: Life Sciences, Biotechnology Keywords: Mortierella; phytohormones; winter wheat seedlings; psychrotrophs
Online: 17 September 2018 (10:10:24 CEST)
The endogenous pool of phytoregulators in plant tissues supplied with microbial secondary metabolites may be crucial for the development of winter wheat seedlings during cool springs. Phytohormones may be synthesized by psychrotrophic microorganisms in lower temperatures occurring in temperate climate. Two fungal isolates from the Spitzbergen soils after the microscopic observations and ITS region molecular characterization were identified as Mortierella antarctica (MA DEM 7) and Mortierella verticillata (MV DEM32). To study the synthesis of indoleacetic acid (IAA) and gibberellic acid (GA) Mortierella strains were grown on media supplemented with precursors of phytohormones (tryptophan or methionine) at 9, 15 and 20 °C for 9 days. The highest amount of IAA synthesis was observed in MV DEM 32 9-day culture at 15 °C with 1.5 mM of tryptophan. At the same temperature the significant promoting effect (about 40% root and shoot fresh weight) of this strain on seedlings was observed. However, only MA DEM 7 had the ACC-deaminase activity with the highest efficiency in 9 °C and at this temperature synthesized IAA without tryptophan also at the same conditions the strain confirmed the strong promoting effect (about 40% root and 24% shoot fresh weight) on seedlings. Both strains synthesized GA in all tested terms and temperatures. Tested Mortierella strains had some important traits to consider them as microbial biofertilizers component improving plant growth in difficult temperate climate.
Fri, 7 September 2018
ARTICLE Download: 233| View: 217| Comments: 0 | doi:10.20944/preprints201809.0128.v1
Subject: Life Sciences, Biotechnology Keywords: Bacillus subtilis; bioemulsifier; cassava wastewater; removal pollutant; methylene blue dye.
Online: 7 September 2018 (10:55:52 CEST)
In this work was investigated the potential of Bacillus subtilis UCP 0146 in the bioconversion of the medium containing 100% of cassava flour wastewater to obtain bioemulsifier. The evaluation of the production was carried out by the emulsification index (IE24) and surface tension (TS). The ionic charge, stability (temperature, salinity and pH measured by IE24 and viscosity), ability to remove and disperse oil and textile dye were investigated. B.subtilis produced an anionic bioemulsifier in the medium containing 100% of cassava wastewater in condition 4 of the factorial design (9% of the inoculum, at 35 °C and agitation of 100 rpm) with surface tension of 39mN/m, IE24 of 95.2 % and yield 2.69 g.L-1. Stability at different pH (2-8), temperatures (0-120ºC) and NaCl, dispersed (55.83 cm2-ODA) and reduced the viscosity of the burned engine oil (90.5 cP) , removed 94.4% petroleum and demonstrated efficiency in methylene blue removal (62.2%). The bioemulsifier and its synthesis from bacteria and also emphases on the role of surfactants in oil remediation.
Wed, 22 August 2018
ARTICLE Download: 237| View: 229| Comments: 0 | doi:10.20944/preprints201808.0390.v1
Subject: Life Sciences, Biotechnology Keywords: botulinum neurotoxin; biosensor; CANARY®, detection; B-cell based assay; immunoassay; food matrices
Online: 22 August 2018 (04:59:24 CEST)
Botulinum neurotoxin (BoNT) intoxication can lead to the disease botulism, characterized by flaccid muscle paralysis that can cause respiratory failure and death. Due to the significant morbidity and mortality costs associated with BoNTs high toxicity, developing highly sensitive, rapid, and field-deployable assays are critically important to protect the nation’s food supply against either accidental or intentional contamination. We report here that the B-cell based biosensor assay (CANARY® Zephyr) detects BoNT/A in buffer and various food matrices rapidly in ≤ 40 min, in small volumes ≈ 50 μL, with minimal processing of samples, and is extremely portable (suitcase-sized equipment). BoNT/A was detected at limits of detection (LOD) < 0.075 ng ± 0.02 in assay buffer while milk matrices (non-fat, 2 %, whole milk) increased the LOD to < 0.175 – 0.314 ng. Limits of detection for the assay in complex foods were < 1 ng ± 0.0 (neutralized acidic juices-carrot, orange and apple); < 16.7 ng ± 7.7 (liquid egg); and varied from < 0. 39 – 3.125 ng for solid complex foods (ground beef, green bean baby puree, smoked salmon). These results show that the CANARY® Zephyr assay can be a highly useful tool in clinical, environmental, and food safety surveillance programs.
Fri, 10 August 2018
REVIEW Download: 203| View: 412| Comments: 0 | doi:10.20944/preprints201808.0204.v1
Subject: Life Sciences, Biotechnology Keywords: Alzheimer's disease; blood-brain barrier; cognitive aging; cognitive impairment; dementia; drug targeting; nanoemulsion; nanocarriers; scavenger receptors
Online: 10 August 2018 (12:28:34 CEST)
A frequent co-morbidity of cerebrovascular pathology and Alzheimer's disease pathology has been observed over past decades. Accordingly, much evidence has been reported which indicates that microvascular endothelial dysfunction, due to cerebrovascular risk factors (e.g., atherosclerosis, obesity, diabetes, smoking, hypertension, aging), precedes cognitive decline in Alzheimer's disease and contributes to its pathogenesis. By incorporating appropriate drug(s) into biomimetic (lipid cubic phase) nanocarriers, one obtains a multitasking combination therapeutic which targets certain cell-surface scavenger receptors, mainly class B type I (i.e., SR-BI), and crosses the blood-brain barrier (BBB). Such targeting allows for various Alzheimer's-related cell types to be simultaneously searched out, in vivo, for localized drug treatment. This in vivo targeting advantage may be particularly important for repurposing an FDA-approved drug, especially one which has shown the added ability to restore some cognitive functions in certain animal models of Alzheimer's disease (e.g., the anticancer drug bexarotene); this (candidate repurposing) drug up to now, by itself (i.e, without nanocarrier), displayed poor CNS penetration in human subjects.
Thu, 26 July 2018
REVIEW Download: 244| View: 241| Comments: 0 | doi:10.20944/preprints201807.0500.v1
Subject: Life Sciences, Biotechnology Keywords: Schizosaccharomyces pombe; oenological uses; maloalcoholic fermentation; stable pigments; wine safety
Online: 26 July 2018 (04:17:59 CEST)
There are numerous yeast species related to wine making, particularly non-Saccharomyces, that deserve special attention due to the great potential they have when it comes to making certain changes in the composition of the wine. Among them, Schizosaccharomyces pombe stands out for its particular metabolism that gives it certain abilities such as regulating the acidity of wine through maloalcoholic fermentation. In addition, this species is characterized by favouring the formation of stable pigments in the wine and releasing large quantities of polysaccharides during ageing on lees. Moreover, its urease activity and its competition for malic acid with lactic acid bacteria make it a safety tool by limiting the formation of ethyl carbamate and biogenic amines in wine. However, it also has certain disadvantages such as its low fermentation speed or the development of undesirable flavours and aromas. In this chapter, the main oenological uses of Schizosaccharomyces pombe that have been proposed in the last years will be reviewed and discussed.
Wed, 25 July 2018
REVIEW Download: 305| View: 190| Comments: 0 | doi:10.20944/preprints201807.0473.v1
Subject: Life Sciences, Biotechnology Keywords: Rnf complex; energy conservation; ferredoxin NAD+ reductase; anaerobic metabolism
Online: 25 July 2018 (09:39:35 CEST)
In the context of the development of bioprocesses for the production of biofuels and bulk chemicals, microbial cells are rationally engineered to produce such molecules at high yield and titres in order to develop new biological methods that satisfy economic constraints. The redox and energetic balances of such strains play crucial roles in performance. Processes performed in strict anaerobes have a limited amount of energy available compared to that in aerobic organisms. This energy is obtained through fermentation and/or ion gradient-driven phosphorylation. Such anaerobic organisms have developed energy conservation mechanisms to increase ATP yields. This paper presents the properties of one of these mechanisms catalysed by the Rnf complex, an ion-translocating membrane complex with a ferredoxin NAD+ oxidoreductase activity. The Rnf complex performs the transfer of electrons from reduced ferredoxin to NAD+ coupled with an ion-motive transport. Ferredoxin is a common electron carrier for anaerobic bacteria and, with NAD+, is involved in several pathways of interest for the production of biofuels. This complex was first identified in Rhodobacter capsulatus and found to be involved in nitrogen fixation. It was then found to be involved in energy conservation in multiple anaerobic organisms, from acetobacteria such as Acetobacterium woodii to sulfate-reducing bacteria such as Desulfovibrio alaskensis and autotrophic bacteria such as Clostridium ljungdahlii and Clostridium aceticum. The Rnf complex triggers two types of ion transports: it can be either a sodium or a proton transporter. Both of these transports create a gradient of ions, generating a membrane potential that is then used by ATPase to produce ATP and thus serving as an energy conservation mechanism. In this review, the available information on the Rnf complex from genetic organization up to its in vivo and in vitro activities in several microorganisms is summarized, with a special focus on the proton-motive Rnf complex.
Mon, 23 July 2018
ARTICLE Download: 169| View: 142| Comments: 0 | doi:10.20944/preprints201807.0435.v1
Subject: Life Sciences, Biotechnology Keywords: Self-assembling peptides, RADA16, (RADA)4, MMP-2, Nanoscaffold, Hausdorff dimension, Fractal
Online: 23 July 2018 (21:56:39 CEST)
(RADA)4 nanoscaffolds are excellent candidates for use as peptide delivery vehicles: they are relatively easy to synthesize with custom bio-functionality, and assemble in situ to allow a focal point of release. This enables (RADA)4 to be utilized in multiple release strategies by embedding a variety of bioactive molecules in an all-in-one ‘construct’. One novel strategy focuses on the local, on-demand release of peptides triggered via proteolysis of tethered peptide sequences. However, the spatial-temporal morphology of self-assembling nanoscaffolds may greatly influence the ability for enzymes to both diffuse into as well as actively cleave substrates. Fine structure and its impact on overall affect on peptide release is poorly understood. In addition, fractal networks observed in nanoscaffolds are linked to the fractal nature of diffusion in these systems. Therefore, matrix morphology and fractal dimension of virgin (RADA)4 and mixtures of (RADA)4 and matrix metalloproteinase 2 (MMP-2) cleavable substrate modified (RADA)4 were characterized over time. Sites of high (GPQG+IASQ, CP1) and low (GPQG+PAGQ, CP2) cleavage activity were chosen. Fine structure was visualized using established according to established methods. After 2 hrs of incubation, nanofiber networks showed an established fractal nature, however nanofibers continued to bundle in all cases as incubation times increased. It was observed that despite extensive nanofiber bundling after 24 hrs of incubation time, the CP1 and CP2 nanoscaffolds were susceptible to MMP-2 cleavage. The properties of these engineered nanoscaffolds characterized herein illustrate that they are an excellent candidate as an enzymatically initiated peptide delivery platform.
Wed, 18 July 2018
REVIEW Download: 257| View: 172| Comments: 0 | doi:10.20944/preprints201807.0329.v1
Subject: Life Sciences, Biotechnology Keywords: bio-sensor; promoter; sensitivity; specificity; high-throughput screening (HTS); genetic promoter chip; “push and pull” mode; toxicity
Online: 18 July 2018 (10:22:39 CEST)
Promoter is a small region of DNA sequence in response to various transcription factors, which initiates a particular gene expression. The promoter-engineered bio-sensor can activate or repress gene expression through transcription factor recognizing specific molecules, such as polyamine, sugars, lactams, amino acids, organic acids or redox molecule, however, the reported applications of promoter enhanced bio-sensor are not too much. This review paper highlights the strategies of construction of promoter-gene engineered bio-sensor with human and bacteria’s genetic promoter array for high-throughput screening (HTS) molecular drugs, study of membrane protein’s localization and nucleocytoplasmic shuttling mechanism of regulating factor, enzyme activity, detection of the toxicity of intermediate chemicals, and probing bacteria density to improve value-added product titer. These bio-sensors’s sensitivity and specificity can be further improved by proposed approaches of Mn2+ and Mg2+ added random Error-prone PCR and site-directed mutagenesis which is applied for construction of bacteria’s “mutant library”. It is expected to establish flexible HTS platform (Bio-sensor array) to large-scale screen transcription factor-acting drugs, reducing the toxicity of intermediate compounds, and constructing gene dynamic regulatory system in “push and pull” mode to effectively regulate the valuable medicinal product production. This proposed novel promoter-engineered biosensors aided synthetic genetic circuit construction will maximize the efficiency of bio-synthesis of medicinal compound, which will greatly promote the development of microbial metabolic engineering and biomedical science.
Mon, 2 July 2018
ARTICLE Download: 287| View: 301| Comments: 0 | doi:10.20944/preprints201807.0014.v1
Subject: Life Sciences, Biotechnology Keywords: beans; iron, zinc and copper bioaccessibility; myo-inositol phosphates; anti-nutrients; polyphenols; household processing
Online: 2 July 2018 (13:19:42 CEST)
Micronutrient deficiencies are a major public health problem. Beans are an important plant-based source of iron, zinc and copper, but their absorption is reduced in the presence of anti-nutrients such as phytates, polyphenols and tannins. Soaking and discarding the soaking water before cooking is unanimously recommended, but this can result in mineral loss. Data on the consequences for mineral bioaccessibility is still limited. This study aimed to evaluate iron, zinc and copper bioaccessibility in black beans cooked (regular pan, pressure cooker) with and without the soaking water. Minerals were quantified by ICP-MS, myo-inositol phosphates (InsP5, InsP6) by HPLC ion-pair chromatography, total polyphenols using Folin-Denis reagent and condensed tannins using Vanillin assay. Mineral bioaccessibility was determined by in vitro digestion and dialysis. All treatments resulted in a statistically significant reduction of total polyphenols (30%) and condensed tannins (20%). Only when discarding the soaking water a loss of iron (6%) and copper (30%) was observed, and InsP6 was slightly decreased (7%) in one treatment. Bioaccessibility of iron and zinc were low (about 0.2% iron and 35% zinc), but copper presented high bioaccessibility (about 70%). Cooking beans under pressure without discarding the soaking water resulted in the highest bioaccessibility levels among all household procedures. Discarding the soaking water before cooking did not improve the nutritional quality of the beans.
Wed, 27 June 2018
REVIEW Download: 439| View: 416| Comments: 0 | doi:10.20944/preprints201806.0451.v1
Subject: Life Sciences, Biotechnology Keywords: aroma; bioflavour; Saccharomyces cerevisiae; synthetic biology; yeast; Yeast 2.0
Online: 27 June 2018 (15:24:02 CEST)
Abstract: Yeast – especially Saccharomyces cerevisiae – have long been a preferred workhorse for the production of numerous recombinant proteins and other metabolites. S. cerevisiae is a noteworthy aroma compound producer, and has also been exploited to produce foreign bioflavour compounds. In the past few years, important strides have been made in unlocking the key elements in the biochemical pathways involved in the production of many aroma compounds. The expression of these biochemical pathways in yeast often involves the manipulation of the host strain to direct the flux towards certain precursors needed for the production of the given aroma compound. This review highlights recent advances in the bioengineering of yeast – including S. cerevisiae – to produce aroma compounds and bioflavours. To capitalise on recent advances in synthetic yeast genomics, this review presents yeast as a significant producer of bioflavours in a fresh context and proposes new directions for combining engineering and biology principles to improve the yield of targeted aroma compounds.
Fri, 22 June 2018
ARTICLE Download: 406| View: 187| Comments: 0 | doi:10.20944/preprints201806.0359.v1
Subject: Life Sciences, Biotechnology Keywords: Parkia biglobosa, alkaline fermentation, vegetable protein, condiment, pH
Online: 22 June 2018 (14:38:29 CEST)
Parkia biglobosa (African locust bean) seed was fermented aerobically to produce a vegetable protein based condiment using various temperature differences and ambient temperature. The rate of fermentation was monitored using three (3) different methods namely: weight loss, pH and Carbon dioxide release. Samples were inoculated using Bacillus subtilis and Saccharomyces cerevisiae as starter culture. During fermentation, several changes occur in the seeds of the African Locust bean. The difference in the weight loss (initial and final weight of the fermenting samples) were used to monitor the rate of fermentation of the African Locust bean (parkia biglobosa) seeds to vegetable protein called ‘Iru’. Fermentation of this seed to ‘Iru’ is an alkaline fermentation, which was confirmed by this work. As means of monitoring the rate of fermentation, the evolution of CO2 was also monitored.
Fri, 15 June 2018
REVIEW Download: 268| View: 242| Comments: 0 | doi:10.20944/preprints201804.0204.v2
Subject: Life Sciences, Biotechnology Keywords: lignocellulosic biomass; laccases; peroxidases; green biochemical; acidophilic microbes
Online: 15 June 2018 (05:51:17 CEST)
The processing of fossil fuels is the major environmental issue today which should be lessen. Biomass is gaining much interest these days as an alternate to energy generation. Lignocellulosic biomass (cellulose, hemicellulose and lignin) is abundant and has been used for a variety of purposes. Among them, the lignin polymer having phenyl-propanoid subunits linked together through C-C bonds or ether linkages, can produce numerous chemicals. It can be depolymerized by microbial activity together with certain enzymes (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Natural organic acids production by fungi has many key roles in nature that are strictly dependent upon organic acid producing fungus type. Fungal enzymatic conversion of lignocellulosic is beneficial over other physiochemical processes. Laccases, the copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), the heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields value-added compounds, the important ones are BTX (Benzene, Xylene and Toluene) and phenols as well as certain polymers like polyurethane and carbon fibers. Thus, this review will provide a concept that biological modifications of lignin using acidophilic microbes can generate certain value added and environment friendly chemicals.
Tue, 12 June 2018
ARTICLE Download: 185| View: 232| Comments: 0 | doi:10.20944/preprints201806.0192.v1
Subject: Life Sciences, Biotechnology Keywords: β4-galactosyltransferase 4; transcriptional mechanism; sensor cells; colon cancer; drug screening
Online: 12 June 2018 (12:51:07 CEST)
The increased expression of β4-galactosyltransferase (β4GalT) 4 was closely associated with poor prognosis of colon cancer. Recently, we showed that the expression of the β4GalT4 gene is regulated by the 0.17 kb core promoter region containing one binding site for Specificity protein 1 (Sp1). To develop a novel screening method for anti-colon cancer drugs, two sensor cell lines having the luciferase gene under the control of two β4GalT4 gene promoters that differed in length were established from SW480 human colon cancer cells. The hGT4-0.17-sensor cells possessed the luciferase reporter driven by the 0.17 kb promoter, while the hGT4-0.3-sensor cells possessed the luciferase reporter driven by the 0.3 kb promoter containing one binding site each for colon cancer-related transcription factors including activator protein 2, E2F, caudal-related homeobox transcription factors, and Runt-related transcription factors besides Sp1. Upon treatment with mitogen-activated protein kinase inhibitor U0126, the promoter activities of the hGT4-0.3-sensor cells decreased significantly, while those of the hGT4-0.17-sensor cells unchanged. These results suggest that the responsiveness to U0126 differs between two sensor cell lines due to the different regulation of the luciferase reporters. This study provides the novel screening method for anti-colon cancer drugs by the combination of two sensor cell lines.
Wed, 6 June 2018
REVIEW Download: 599| View: 279| Comments: 0 | doi:10.20944/preprints201806.0073.v1
Subject: Life Sciences, Biotechnology Keywords: wastewater treatment; microbial fuel cells; bioenergy
Online: 6 June 2018 (05:38:03 CEST)
Microbial Fuel Cells (MFCs) representing a promising technology for the extract of energy and resources through wastewater and it also offer an economic solution to the problem of environment effluent and energy crisis in near future. The advance device is rather appealing, due its potential benefits, its practical application is, however hindered by several drawbacks, such an internally competing microbial reaction, and low power generation. This report is an endeavor to address various design connected to the MFCs application to wastewater treatment, in particular cost effective bioelectricity from waste water are reviewed and discussed with a multidisciplinary approach. The conclusions drawn herein can be of practical interest to all new researchers dealing with effluent wastewater treatment using MFCs.
Wed, 30 May 2018
ARTICLE Download: 293| View: 472| Comments: 0 | doi:10.20944/preprints201805.0456.v1
Subject: Life Sciences, Biotechnology Keywords: monoclonal antibody; immunoglobulin G; glycosylation; Chinese hamster ovary; perfusion cell culture; continuous biomanufacturing
Online: 30 May 2018 (16:52:12 CEST)
A critical quality attribute of therapeutic monoclonal antibodies (mAbs) is the terminal sugar molecules of the N-linked glycan attached to the fragment crystalizable (Fc) region. There exists naturally-occurring heterogeneity in the N-linked glycan structure of mAbs, and such heterogeneity has a significant influence on the clinical safety and efficacy of mAb drugs. We previously proposed a constraint-based modeling method called glycosylation flux analysis (GFA) to characterize the rates (fluxes) of intracellular glycosylation reactions and applied the method to examine the N-linked glycosylation of immunoglobulin G (IgG) in fed-batch Chinese hamster ovary (CHO) fed-batch cultivations. In this work, we significantly improved the computational efficiency of the GFA, and employed the method to analyze the glycosylation of IgG in continuous perfusion CHO cultivations. Perfusion cell cultures have several advantages over the traditional (fed-)batch operation, including higher productivity per unit volume of reactor and more consistent product quality. The GFA showed that as in the fed-batch cultivation, the dynamical changes of IgG glycan heterogeneity in the perfusion culture are mainly attributed to alterations in the galactosylation flux activity. Furthermore, a regression analysis of the galactosylation flux activity using random forest regression linked the dynamics of galactosylation activity with the cell-specific productivity of IgG and the extracellular ammonia concentration.
Mon, 23 April 2018
REVIEW Download: 329| View: 183| Comments: 0 | doi:10.20944/preprints201804.0275.v1
Subject: Life Sciences, Biotechnology Keywords: advanced therapy, aggressive, antisocial, behavior, MAOA
Online: 23 April 2018 (08:12:15 CEST)
Antisocial behavior is a behavior disorder inherited according to the inheritance of X-linked chromosome. Mutations in the MAOA gene can cause different behaviors in humans. These can comprise violent behavior or antisocial behavior. Low MAOA (MAOA-L) allele activity can cause antisocial behavior in both healthy and unhealthy people. Antisocial from healthy males can originate from maltreatment during childhood. There are no drugs for the treatment of antisocial behavior permanently at this time. MAOA inhibitor can reverse antisocial behavior in animal models. To cure antisocial behavior in the future, the CRISPR/Cas9 system in combination with iPSCs or ssODN methods for instance can be used. This system has succeeded to correct erroneous segments in the F8 gene and F9 gene. Both genes occupy the X chromosome. The MAOA gene also occupies the X chromosome. It seems that CRISPR/Cas9 system may be a beneficial tool to edit erroneous segments in the MAOA gene to treat antisocial behavior.
Fri, 20 April 2018
REVIEW Download: 337| View: 426| Comments: 1 | doi:10.20944/preprints201804.0264.v1
Subject: Life Sciences, Biotechnology Keywords: designed consortium; textile effluents; biological induction; azo dyes
Online: 20 April 2018 (11:25:43 CEST)
The potential of biological consortia designed for laccase production and dye treatment is discussed in this review. The poor yields in laccase production and low efficiency in dye decolorization of monoculture-based treatments has encouraged the use of designed biological consortia. A consortium is a system where the growth of two or more organisms, chosen to improve a particular bioprocess, is induced in the same medium. Chemical and natural mediators are being replaced by consortia for the production of laccases because, in addition to being less toxic, they induce new enzyme isoforms and lead to high laccase yields. On the other hand, consortia act synergistically in the decolorization of azo dyes through the enzymes they produce, so overall degradation is improved. Designed consortia are an attractive alternative still in development that could provide new biotechnological tools for the treatment of textile effluents.
ARTICLE Download: 258| View: 249| Comments: 0 | doi:10.20944/preprints201804.0262.v1
Subject: Life Sciences, Biotechnology Keywords: hepatic injury; sealants; metalloproteinases; inflammatory response; wound healing
Online: 20 April 2018 (11:14:49 CEST)
Background. Adhesives and sealants can be used to repair and preserve solid damaged organs. This study explores the activity of different matrix metalloproteinases (MMP) during the healing of liver injuries treated with two biological adhesives (Tachosil and GelitaSpon) and a new synthetic elastic cyanoacrylate (Adhflex®). Methods. Liver traumatic injuries were experimentally induced in 90 male Wistar rats using a Stiefel biopsy punch in the liver. Wound healing was evaluated 2, 6, and 18 days after injury by determining MMP1, 2, 8, 9, and 13 expression. The histopathological repair was assessed by hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining. The three sealants used supported complete healing of the liver lesions. Both histopathology and MMP findings indicate that the degradation process of Adhflex® is slower and produces a strong initial inflammatory reaction. Results. All the MMPs measured disclosed higher values at early stage of the healing process in animals treated with Adhflex® and Tachosil, being the expression of for MMP2 and MMP9 significantly higher in the Adhflex-treated group. Animals treated with Tachosil had significant higher values of MMP8 and MPP13 than the Adhflex-treated group. Animals treated with Adhflex® showed a maintained overexpression in all the MMPs tested even at the latest wound healing stages. Conclusion. Notably, this MMPs overexpression did not influence negatively the histological healing process of the hepatic injuries. Given that all hepatic trauma injuries should be considered emergencies, any easy-to-use and rapid sealant, such as Adhflex®, could be considered as a suitable treatment option.
Mon, 16 April 2018
TECHNICAL NOTE Download: 298| View: 391| Comments: 0 | doi:10.20944/preprints201804.0211.v1
Subject: Life Sciences, Biotechnology Keywords: bone graft, resorbable barrier, sinus lift, heterologous cortical lamina
Online: 16 April 2018 (13:53:55 CEST)
Abstract A variety of surgical techniques have been developed to reconstruct the posterior maxilla when bone volume is insufficient. A barrier membrane or bone window pushed inside the sinus cavity as the ‘‘roof’’ of the sinus cavity for preserve the space and help bone. The heterologous cortical lamina is used for the mechanical support, without any grafting material, of sinus membranes resulting in only bone tissue formation and not mixed with the graft.
REVIEW Download: 233| View: 227| Comments: 0 | doi:10.20944/preprints201804.0204.v1
Subject: Life Sciences, Biotechnology Keywords: lignocellulosic biomass; laccases; peroxidases; green biochemical; acidophilic microbes
Online: 16 April 2018 (10:36:26 CEST)
Lignocellulosic feedstock (cellulose, hemicellulose and lignin) has been used for a variety of purposes. Among them, lignin can produce value-added chemicals having phenyl-propanoid subunits known as core lignin, possessing either C-C bonds or ether linkages. It can be depolymerized by microbial activity together with certain enzymes (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Natural organic acids production by fungi has many key roles in nature that are strictly dependent upon organic acid producing fungus type. Enzymatic conversion of lignocellulosic is beneficial over other physiochemical processes. Laccases, the copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), the heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields polyaromatics, the important ones are BTX (Benzene, Xylene and Toluene), found in several different configurations. However, most modern aromatics complexes enhance the production of p-xylene, benzene and sometimes o-xylene respectively. Thus, this review will provide a concept that chemical and biological modifications of lignin yield certain value added and environment friendly chemicals.
Wed, 4 April 2018
ARTICLE Download: 242| View: 295| Comments: 0 | doi:10.20944/preprints201804.0044.v1
Subject: Life Sciences, Biotechnology Keywords: electromyography; human-computer interface; motor control; pattern classification; artificial neural networks
Online: 4 April 2018 (05:07:22 CEST)
Recent advances in recording and real-time analysis of surface electromyographic signals (sEMG) have fostered the use of sEMG human-machine interfaces for controlling personal computers, prostheses of upper limbs, and exoskeletons among others. Despite a relatively high mean performance, sEMG-interfaces still exhibit strong variance in the fidelity of gesture recognition among different users. Here we systematically study the latent factors determining the performance of sEMG-interfaces in synthetic tests and in an arcade game. We show that the degree of muscle cooperation and the amount of the body fatty tissue are the decisive factors in synthetic tests. Our data suggest that these factors can only be adjusted by a long-term training, which promotes fine-tuning of low-level neural circuits driving the muscles. A short-term training has no effect on synthetic tests, but significantly increases the game scoring. This implies that it works at a higher decision-making level, not relevant for synthetic gestures. We propose a procedure that enables quantification of the gestures’ fidelity in a dynamic gaming environment. For each individual subject the approach allows identifying “problematic” gestures that decrease gaming performance. This information can be used for optimizing the training strategy and for adapting the signal processing algorithms to individual users, which could be a way for a qualitative leap in the development of future sEMG-interfaces.
Tue, 27 March 2018
REVIEW Download: 305| View: 398| Comments: 0 | doi:10.20944/preprints201803.0227.v1
Subject: Life Sciences, Biotechnology Keywords: Antivenom; snakebite; small molecule toxin inhibitors; oligonucleotides; antibodies; phage display; next generation antivenom; recombinant antivenom
Online: 27 March 2018 (13:41:46 CEST)
With the inclusion of snakebite envenoming on the World Health Organisation’s list of Neglected Tropical Diseases, an incentive has been established to promote research and development effort in novel snakebite antivenom therapies. Different technological approaches are being pursued by different research groups, including the use of small molecule inhibitors against enzymatic toxins, as well as peptide and oligonucleotide-based aptamers and antibody-based biotherapeutics against both enzymatic and non-enzymatic toxins. In this article, the most recent advances in these fields are presented, and the advantages, disadvantages, and feasibility of using different toxin-neutralizing molecules are reviewed. Particular focus within small molecules is directed towards the inhibitors, varespladib, batimastat, and marimastat, while in the field of antibody-based therapies, novel recombinant polyclonal plantivenom technology is discussed.
Wed, 21 March 2018
REVIEW Download: 577| View: 559| Comments: 0 | doi:10.20944/preprints201803.0189.v1
Subject: Life Sciences, Biotechnology Keywords: batch; biopolyesters; bioreactor; cell recycling; continuous; chemostat; fed-batch; fermentation; pH-stat; polyhydroxyalkanoate (PHA)
Online: 21 March 2018 (13:01:12 CET)
Polyhydroxyalkanoates (PHA) are microbial biopolyesters utilized as “green plastics”. Their production under controlled conditions resorts to bioreactors operated in different modes. Because PHA biosynthesis constitutes a multiphase process, both feeding strategy and bioreactor operation mode need smart adaptation. Traditional PHA production setups based on batch, repeated batch, fed-batch or cyclic fed-batch processes are often limited in productivity, or display insufficient controllability of polyester composition. For highly diluted substrate streams like it is the case for (agro)industrial waste streams, fed-batch enhanced by cell recycling were recently reported as a viable tool to increase volumetric productivity. As emerging trend, continuous fermentation processes in single-, two-, and multi-stage setups are reported, which bring the kinetics of both microbial growth and PHA accumulation into agreement with process engineering, and allow tailoring PHA´s molecular structure. Moreover, we currently witness an increasing number of CO2-based PHA production processes using cyanobacteria; these light-driven processes resort to photobioreactors similar to those used for microalgae cultivation, and can be operated both discontinuously and continuously. This development goes in parallel to the emerging use of methane and syngas as an abundantly available gaseous substrates, which also calls for bioreactor systems with optimized gas transfer. The review sheds light on the challenges of diverse PHA production processes in different bioreactor types and operational regimes using miscellaneous microbial production strains such as extremophilic Archaea, chemoheterotrophic eubacteria and phototrophic cyanobacteria. Particular emphasize is dedicated to the limitations and promises of different bioreactor-strain combinations, and to efforts devoted to upscaling these processes to industrially relevant scales.
Fri, 2 March 2018
ARTICLE Download: 353| View: 425| Comments: 0 | doi:10.20944/preprints201803.0019.v1
Subject: Life Sciences, Biotechnology Keywords: diffusion; gas transfer; fermentation; uptake rate; physio-chemical
Online: 2 March 2018 (07:01:22 CET)
Current education in biology is devoid of mathematics in many countries, probably because many relevant biological processes are explained from a qualitative point of view rather than addressing the quantitative aspects of these phenomena. Here, we employ a case study from the yeast physiology to illustrate the importance of numeracy skills for a deeper understanding of relevant biological problems. Yeast anaerobic growth on sugars is a widespread process as it is the basis for beer, bread, and winemaking and it is much akin to lactic acid fermentation in muscle cells in response to an increased energy demand. To study the physiology of yeasts under controlled conditions and being able to compare the results quantitatively, one ought to perform measurements and calculations involving concentrations of oxygen, biomass, and organic compounds. To set-up an “anaerobic” culture of Saccharomyces cerevisiae in a defined medium, one needs to calculate how much oxygen must enter the cultivation system, to meet the requirements for ergosterol and oleic acid biosyntheses, both of which require oxygen. Using basic physicochemical principles and simple mathematical skills, students will be able to compute the oxygen requirement for yeast growth under such “anaerobic” conditions.
Wed, 28 February 2018
REVIEW Download: 306| View: 255| Comments: 0 | doi:10.20944/preprints201802.0190.v1
Subject: Life Sciences, Biotechnology Keywords: Alzheimer’s disease; biomimetic nanocarriers; blood-brain barrier; dementia; drug targeting; lipid cubic phases; nanoemulsion; SR-BI; scavenger receptors
Online: 28 February 2018 (07:49:13 CET)
Over past decades, a frequent co-morbidity of cerebrovascular pathology and Alzheimer's disease pathology has been observed. Numerous published studies indicate that preservation of healthy cerebrovascular endothelium can be an important therapeutic target. By incorporating appropriate drug(s) into biomimetic (lipid cubic-phase) nanocarriers, one obtains a multitasking combination therapeutic which targets certain cell-surface scavenger receptors, mainly class B type 1 (i.e., SR-BI), and crosses the blood-brain barrier. This targeting allows for various Alzheimer’s-related cell types to be simultaneously searched out for localized drug treatment in vivo.
Tue, 6 February 2018
REVIEW Download: 434| View: 406| Comments: 0 | doi:10.20944/preprints201802.0051.v1
Subject: Life Sciences, Biotechnology Keywords: metals; dental regeneration; bioactivity; tissue regeneration; bone
Online: 6 February 2018 (05:25:46 CET)
The regeneration of bone tissue is a main purpose of most therapies in dental medicine. For bone regeneration, calcium phosphate (CaP)-based substitute materials based on natural (allo- and xenografts) and synthetic origins (alloplastic materials) are applied for guiding the regeneration processes. The optimal bone substitute has to act as a substrate for bone ingrowth into a defect, while it should be resorbed even in the time frame needed for complete regeneration up to the condition of restitution ad integrum. In this context, the modes of action of CaP-based substitute materials have been frequently investigated and it has been shown that such materials strongly influence regenerative processes such as osteoblast growth or differentiation and also on osteoclastic resorption due to different physicochemical properties of the materials. However, the material characteristics needed for the required ratio between the formation of new bone tissue and material degradation has not been found until now. The addition of different substances such as collagen or growth factors and also of different cell types have already been tested but did not allow for sufficient or prompt application. Moreover, metals or metal ions are differently used as basis or as supplement for different materials in the field of bone regeneration. Moreover, it has already been shown that different metal ions are integral components of bone tissue playing functional roles in the physiological cellular environment as well as in the course of bone healing. The present review focuses on frequently used metals as integral parts of materials designated for bone regeneration with the aim to give an overview of currently existing knowledge about the effects of metals in the field of bone regeneration.
Tue, 23 January 2018
REVIEW Download: 429| View: 597| Comments: 0 | doi:10.20944/preprints201801.0218.v1
Subject: Life Sciences, Biotechnology Keywords: Biocompatibility; Biodegradability; Biopolyesters; Biopolymers; Composites; Drug Release; Implants; Polyhydroxyalkanoates; Scaffolds; Tissue Engineering
Online: 23 January 2018 (16:49:05 CET)
Polyhydroxyalkanotes (PHA) are bio-based microbial biopolyesters with stiffness, elasticity, crystallinity and degradability tunable by the monomeric composition, bio-production strategy and post-synthetic processing; they display biological alternatives for diverse technomers of petrochemical origin. This, together with the fact that their monomeric and oligomeric in vivo degradation products do not exert any toxic or elsewhere negative effect to living cells or tissue of humans or animals, makes them highly stimulating for various applications in the medical field. The article provides an overview of PHA application in the therapeutic, surgical and tissue engineering area, and reviews strategies to produce PHA at purity levels high enough to be used in vivo. Tested applications of differently composed PHA and advanced follow-up products as carrier materials for controlled in vivo release of anti-cancer drugs or antibiotics, as scaffolds for tissue engineering, as guidance conduits for nerve repair or as enhanced sutures, implants or meshes are discussed from both a biotechnological and a material-scientific perspective. Particular attention is devoted to the adaptation of traditional polymer processing techniques for production of medicine-related devices based on PHA, such as melt-spinning, melt extrusion, or solvent evaporation, and to emerging processing techniques like 3D-printing, computer-aided wet-spinning, laser perforation, or electrospinning.
Mon, 22 January 2018
REVIEW Download: 2072| View: 406| Comments: 0 | doi:10.20944/preprints201801.0198.v1
Subject: Life Sciences, Biotechnology Keywords: extromphiles; extremophilic bacteria; enzymes; biotechnology application
Online: 22 January 2018 (10:22:21 CET)
Extremophilic bacteria are important groups of extremophilic organisms that have been studied during the last years. They are considered as a source of enzymes due to great diversity and can survive under extreme conditions. Many enzymes produced by these microorganisms are of great importance and have found applications in several industries. Due to their activity and stability under extreme conditions, these enzymes offer new alternatives for current biotechnological and industrial applications. They have a wide range of potential uses and have been a nuclear subject of many different investigations. To date, some of the enzymes produced by extremophilic bacteria are currently being assessed thier industrials applications. Despite, benefits that present these enzymes, their potentials remain largely unexplored. These enzymes pose new opportunities for new line of research, and biotechnological applications. This review provides a summary on diversity and biotechnological and industrial applications of some enzymes produced by extremophilic bacteria.
Tue, 16 January 2018
ARTICLE Download: 430| View: 454| Comments: 0 | doi:10.20944/preprints201801.0137.v1
Subject: Life Sciences, Biotechnology Keywords: ice-binding proteins; antifreeze proteins, cold finger, ice affinity purification.
Online: 16 January 2018 (07:56:40 CET)
Ice-binding proteins (IBPs) have several functions that permit their hosts to thrive in the presence of ice. The ability of IBPs to control ice growth makes them potential additives in various industries ranging from food storage and cryopreservation to anti-icing systems. For IBPs to be used in commercial applications, however, methods are needed to produce sufficient quantities of high-quality proteins. Here, we describe a new method for IBP purification, termed falling water ice purification (FWIP). The method is based on the affinity of IBPs for ice. A crude IBP solution is allowed to flow continuously over the large chilled vertical surface of a commercial ice machine. The temperature of the surface is lowered gradually until ice crystals are produced, to which the IBPs bind but other solutes do not. As in other ice affinity methods, FWIP does not require molecular tags and is suitable for purifying recombinant IBPs as well as IBPs from natural sources. The advantage of FWIP over other ice affinity methods is that it exploits an ice machine designed to produce large volumes of clear ice daily. This system can be easily scaled up and suits the purification of industrial quantities of IBPs. The FWIP method significantly advances the use of IBPs in research and industry.
Mon, 8 January 2018
ARTICLE Download: 458| View: 322| Comments: 0 | doi:10.20944/preprints201801.0068.v1
Subject: Life Sciences, Biotechnology Keywords: Activities of Daily Living (ADL); environment; sensors; mobile devices, framework; data acquisition; data processing; data fusion; pattern recognition; machine learning
Online: 8 January 2018 (11:34:36 CET)
Sensors available on mobile devices allow the automatic identification of Activities of Daily Living (ADL). This paper describes an approach for the creation of a framework for the identification of ADL, taking in account several concepts, including data acquisition, data processing, data fusion, pattern recognition, and machine learning. These concepts can be mapped in a module of the framework, including the use and creation of several algorithms. For the development of a framework that works in several conditions, e.g., without Internet connection, these algorithms should take in account the hardware and software limitations of the mobile devices to run all main tasks locally. The main purpose of this paper is related to the presentation the sensors, algorithms, and architecture of the proposed approach.
ARTICLE Download: 1310| View: 829| Comments: 0 | doi:10.20944/preprints201801.0055.v1
Subject: Life Sciences, Biotechnology Keywords: orange peel essential oil; green extraction; liquid whole eggs; biopreservation; shelf-life
Online: 8 January 2018 (09:22:37 CET)
A possible way to valorize citrus peels, which are byproducts of the juice extraction industry, is to use them as natural biopreservatives. In this paper we present early results from a compared Solvent Free Microwave Extraction (SFME) with Hydro-Distillation (HD) and Cold Pressing (CP) of essential oils (EOs) using fresh orange peel (Citrus sinensis L. var. Valencia late), a by-product in the production of orange juice in Algeria. The EOs were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). All extracted C. sinensis EOs were chemotype limonene (94.64 to 95.48%). SFME is performed without added any solvent or water. SFME increases EO yield and eliminate wastewater treatment, resulting in a great progress in terms of time and cost efficiency. In its second part, the present study was conducted to evaluate “in vitro”, the antioxidant activities of Solvent Free Microwave (SFM) extracted orange EO by using the DPPH• (2,2-di-phenyl-1-picrilhydrazyl) free radical scavenging assay. The ability of orange EO to scavenge the free radical DPPH• was high, exceeding 80%. The result of the DPPH assay gives an IC50 range value of 89.25 μg/mL (0.09 mg/mL) for the studied sample. Accordingly to the scientific literature, C. sinensis EO tested in the present study presented strong antioxidant activity, when looking to its values of AAI = 1.12 μg/mL. The feasibility of biopreservation used EOs as an alternative to synthetic techniques for liquid whole egg (LWE) stored under commercial retail conditions was investigated. The orange EO extracted by SFM was screened for its antibacterial and antioxidant activities in LWE at concentrations of 0.1, 0.3 and 0.5%. The TBA-RS results showed that the EO treatments significantly (p < 0.05) reduced the lipid oxidation in LWE. The long term oxidative, microbial and organoleptical stability of the LWE during display was positively influenced by orange EO treatments. Therefore, the results obtained here confirm that EO treatment as a promising technology to extend the commercial shelf-life of liquid egg products during retail/display.
Thu, 30 November 2017
ARTICLE Download: 584| View: 373| Comments: 0 | doi:10.20944/preprints201711.0202.v1
Subject: Life Sciences, Biotechnology Keywords: bacterial inactivation; drinking water; electromagnetic fields; electroporation; Escherichia coli
Online: 30 November 2017 (11:22:25 CET)
Bacteria play a key role in both human health and disease. One of the most prevalent harmful bacteria is E. coli which is responsible for several illnesses ranging from diarrhea, stomach cramp and fever. In this work we explore the application of moderate electric or magnetic fields for treating deionized water that is contaminated with E. coli. We found that moderate alternating electric (AC) fields (10 V/cm to 1kV/cm) and moderate static magnetic fields (10 to 65 mT) can significantly inactivate E. coli by up to 90% or more. This provides the possibilities of developing a low cost and a practical bacteria inactivation technique using electric or magnetic fields.
Thu, 16 November 2017
ARTICLE Download: 350| View: 395| Comments: 0 | doi:10.20944/preprints201711.0110.v1
Subject: Life Sciences, Biotechnology Keywords: Fluorescent reporter; E2-Crimson; mouse embryonic stem cells; knock-in; in vivo imaging
Online: 16 November 2017 (17:46:53 CET)
Far-red fluorescent reporter genes can be used for tracking cells non-invasively in vivo using fluorescence imaging. Here, we investigate the effectiveness of the far-red fluorescent protein, E2-Crimson (E2C), for tracking mouse embryonic cells (mESCs) in vivo following subcutaneous administration into mice. Using a knock-in strategy, we introduced E2C into the Rosa26 locus of an E14-Bra-GFP mESC line, and after confirming that the E2C had no obvious effect on the phenotype of the mESCs, we injected them into mice and imaged them over 9 days. The results showed that fluorescence intensity was weak, and cells could only be detected when injected at high densities. Furthermore, intensity peaked on day 4 and then started to decrease, despite the fact that tumour volume continued to increase beyond day 4. Histopathological analysis showed that although E2C fluorescence could barely be detected in vivo at day 9, analysis of frozen sections indicated that all mESCs within the tumours continued to express E2C. We hypothesise that the decrease in fluorescence intensity in vivo was probably due to the fact that the mESC tumours became more vascular with time, thus leading to increased absorbance of E2C fluorescence by haemoglobin. We conclude that the E2C reporter has limited use for tracking cells in vivo, at least when introduced as a single copy into the Rosa26 locus.
Fri, 13 October 2017
ARTICLE Download: 404| View: 459| Comments: 0 | doi:10.20944/preprints201710.0083.v1
Subject: Life Sciences, Biotechnology Keywords: coffee; grape juice; immunosensing; mycotoxins; nanobiosensors; wine; microcantilever
Online: 13 October 2017 (03:42:50 CEST)
Mycotoxins food contamination represents a serious risk for consumers health. They are secondary metabolites of fungi that can be present in a wide range of foodstuffs. Ochratoxin A (OTA) is one of the most toxic compound and it is classified as a possible carcinogenic molecule. The harmful effects of OTA on human and animal health lead to a big boost to develop and optimize highly sensitive and accurate methods for OTA detection. An innovative and rapid detection method based on microcantilever resonators for ochratoxin A identification in food matrix has been developed. This work demonstrates the possibility to apply microcantilever technology in food safety field, showing for the first time in literature the successful detection of one of the most dangerous mycotoxin in different food matrixes both solids and liquids, such as green coffee, grape juice and wine. Sensing performances are discussed in terms of calibration plot and limit of detection.
Thu, 21 September 2017
ARTICLE Download: 604| View: 465| Comments: 0 | doi:10.20944/preprints201709.0102.v1
Subject: Life Sciences, Biotechnology Keywords: drug screening； bone mineralization； osteoclast； zebrafish
Online: 21 September 2017 (06:34:11 CEST)
Currently, drug screening is primarily based on human cell culture for initial high-throughput screening, and subsequently, rodent model to confirm the biological effects. However, the mammalian system is known for time-consuming and highly-cost to be difficult to perform high-throughput drug screening, which exists a critical gap between in vitro cell-based models and the in vivo mammalian models. Therefore, the zebrafish could bridge this gap in preclinical toxicity screening along the drug development pipeline because of its efficiency. We aimed to develop an in vivo zebrafish platform for rapid drug screening. Zebrafish, due to its high genomic conservation with mammals and rapid development and differentiation, it has many advantages, such as short life span, large number of offspring and low cost, easy manipulation for generating transgenic species, to serve as animal model for disease-based research. In 96-well microplates, zebrafish embryos were incubated with small molecular compounds that affected bone mineralization. The level of osteogenic mineralization was evaluated by fluorescent dye staining and quantified by image analysis software. Quantitative real time-PCR (qRT-PCR) was performed to evaluate the biological pathways involved in bone metabolism at the molecular level. The system was validated by demonstrating that response to alendronate and Dorsomorphin in zebrafish. In our study, we screened for 24 compounds within the CYCU-1120~1152 chemical library and identified 3 compounds, pentamidine (CYCU-1140), BML-267 (CYCU-1147), and alendronate (CYCU-1152), increased embryonic mineralization; while 6 compounds, RWJ-60475 (CYCU-1126), levamisole HCL (CYCU-1128), tetramisole HCL (CYCU-1129), fenvalerate (CYCU-1132), NSC-663284 (CYCU-1138), and BML-267ester (CYCU-1148), were inhibitory to bone mineralization. We also found that alendronate enhanced the level of bone mineralization by inhibiting osteoclast-related genes. To sum up, our research showed that zebrafish may have potential to be a drug-screening and mechanism-analysis platform for bone mineralization.
Fri, 8 September 2017
REVIEW Download: 435| View: 422| Comments: 0 | doi:10.20944/preprints201709.0027.v1
Subject: Life Sciences, Biotechnology Keywords: EVs; endothelial-derived microparticles; platelet-derived microparticles; non-invasive biomarkers; miRNAs signature; diabetes associated complications; micro-macrovascular damage; diabetic nephropathy
Online: 8 September 2017 (09:38:47 CEST)
Extracellular vesicles (EVs) represent a heterogeneous population of small vesicles, consisting of a phospholipidic bilayer surrounding a soluble interior cargo. Almost all cell types release EVs, thus they are naturally present in all body fluids. Among the several potential applications, EVs could be used as drug delivery vehicles in disease treatment, in immune therapy because of their immunomodulatory properties and in regenerative medicine. In addition to general markers, EVs are characterized by the presence of specific biomarkers (proteins, miRNAs) that allow the identification of their cell- or tissue-origin. For these features, they represent a potential powerful diagnostic tool to monitor state and progression of specific diseases. As regards, a large body of studies supports the idea that endothelial derived (EMPs) together with platelet-derived microparticles (PMPs) are deeply involved in the pathogenesis of diseases characterized by micro- and macrovascular damages, including diabetes. Existing literature suggests that the detection of circulating EMPs and PMPs and their specific miRNA profile may represent a very useful non-invasive signature to achieve informations about the onset of peculiar disease manifestations. In this Review, we discuss the possible utility of EVs in the early diagnosis of diabetes-associated microvascular complications, specifically related to kidney.
Sun, 27 August 2017
ARTICLE Download: 564| View: 572| Comments: 0 | doi:10.20944/preprints201708.0096.v1
Subject: Life Sciences, Biotechnology Keywords: CTR1 metal-binding extracellular domain cloning; copper/silver chelation; E. coli filamentous growth; secondary silver nanoparticles formation
Online: 27 August 2017 (11:56:08 CEST)
There is much interest in effective copper chelators to correct copper dyshomeostasis in neurodegenerative and oncological diseases. In this study, a recombinant fusion protein for expression in E. coli cells was constructed from glutathione-S-transferase (GST) and the N-terminal domain (ectodomain) of human high affinity copper transporter CTR1 (hNdCTR1), which has three metal-bound motifs. Several biological properties of the GST-hNdCTR1 fusion protein were assessed. It was demonstrated that in cells, the protein was prone to oligomerization, formed inclusion bodies and displayed no toxicity. Treatment of E. coli cells with copper and silver ions reduced cell viability in a dose- and time-dependent manner. Cells expressing GST-hNdCTR1 protein demonstrated resistance to the metal treatments. These cells accumulated silver ions and formed nanoparticles that contained AgCl and Ag0. In this bacterial population, filamentous bacteria with length about 10 μm were often observed. The possibility for the fusion protein carrying extracellular metal binding motifs to integrate into the cell’s copper metabolism and its chelating properties are discussed.
Fri, 14 April 2017
ARTICLE Download: 573| View: 567| Comments: 0 | doi:10.20944/preprints201704.0085.v1
Subject: Life Sciences, Biotechnology Keywords: lipid extracted microalgae, isoprenoids, detoxification
Online: 14 April 2017 (09:11:15 CEST)
Microalgae are recognized as a third generation feedstock for biofuel production due to its rapid growth rate and lignin-free characteristic. In this study, the lipid extracted microalgae biomass residues was used as the material to produce isoprene, α-pinene and β-pinene with the engineered E. coli strain. We adopted an optimal sulfuric acid hydrolysis method to convert holocellulose into fermentable sugar efficiently (6.37 g/L) and explored a novel detoxification strategy (phosphoric acid/calcium hydroxide) to remove inhibitors notably. 55.32 % acetic acid, 99.19 % furfural and 98.22 % 5-HMF were cut down with the phosphoric acid/calcium hydroxide method, and the fermentation concentration of isoprene (223.23 mg/L), α-pinene (382.21 μg/L) and β-pinene (17.4 mg/L) using the detoxified hydrolysate as the carbon source account for approximately 86.02 %, 90.16 % and 88.32 % of those produced by the engineered E. coli strain fermented on pure glucose, respectively.
Thu, 30 March 2017
ARTICLE Download: 690| View: 708| Comments: 0 | doi:10.20944/preprints201703.0222.v1
Subject: Life Sciences, Biotechnology Keywords: bioethanol, fruits, Corn Threshing Residue, fermentation, distillation
Online: 30 March 2017 (17:49:30 CEST)
Alcoholic fermentations were performed adapting the technology to exploit the residual thermal energy (hot water at 83-85°C) of a cogeneration plant and to valorize agricultural wastes. Substrates were apple, kiwifruit and peaches wastes and Corn Threshing Residue (CTR). Saccharomyces bayanus was chosen as biocatalyst. The fruits, fresh or blanched, were mashed; CTR was gelatinized and liquefied by adding Liquozyme® SC DS (Novozyme); saccharification simultaneous to fermentation was carried out using the enzyme Spirizyme® Ultra (Novozyme). Lab-scale static fermentations were carried out at 28°C and 35°C, using raw fruits, blanched fruits and CTR, monitoring the ethanol production. The highest ethanol production was reached with CTR (10,22%9 and among fruits with apple (8,71%). Distillations at low temperatures and under vacuum, to exploit warm water from cogeneration plant, were tested; distillation at 80°C and 200 mbar or 400 mbar allowed to recover 93,35 and 89,59 % of ethanol respectively. These results support a fermentation process coupled to a cogeneration plant, fed with apple wastes and with CTR when apple wastes are not available, where hot water from cogeneration plant is used in blanching and distillation phases. The scale up in a pilot plant was also carried out.
ARTICLE Download: 890| View: 829| Comments: 0 | doi:10.20944/preprints201703.0218.v1
Online: 30 March 2017 (16:22:32 CEST)
In the present study, an attempt was made to induce rooting from single-node cuttings of hybrid aspen (Populus tremula L. ×P. tremuloides Michx.) with different concentrations of IAA, IBA and NAA during rooting. Among the three auxins used, NAA showed more effective induction on rooting as compared to IAA and IBA at the whole level. Thereafter, NAA was used further in experiments for anatomical and biochemical investigation. The results showed that it took 12 days from the differentiation of primordium to the appearance of young adventitious roots with NAA application. It was found that endogenous IAA, ZR and GA3 levels increased, but ABA decreased in cuttings with 0.54 mM NAA treatment. In contrast to the endogenous IAA level, NAA had negative effect on IAA-oxidase (IAAO) activity. Similarly, the decreased peroxidase (POD) activity, consistent with down-regulation of expressed levels of POD1 and POD2, was observed in NAA-treated cuttings. Whereas, NAA resulted in a higher activity in polyphenol oxidase (PPO) compared to the control cuttings. Collectively, the study highlighted that 0.54 mM NAA is efficient on rooting in hybrid aspen, and its effect on metabolic changes during rooting is discussed, which provide valuable information for propagating hybrid aspen.
Wed, 1 March 2017
ARTICLE Download: 776| View: 702| Comments: 0 | doi:10.20944/preprints201703.0004.v1
Subject: Life Sciences, Biotechnology Keywords: fumaric acid; purification; spent sulfite liquor; biorefineries
Online: 1 March 2017 (09:41:31 CET)
Fumaric acid is a chemical building block with many applications, namely in the polymer industry. The fermentative production of fumaric acid from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. The use of existing industrial side-streams as raw-material within biorefineries potentially enable production costs competitive against current chemical processes, while preventing the use of refined sugars competing with food and feed uses and avoiding purposely grow crops requiring large areas of arable land. However, most industrial side streams contain a diversity of molecules that will add complexity to the purification of fumaric acid from the fermentation broth. A process for the recovery and purification of fumaric acid from complex fermentation medium containing spent sulfite liquor (SSL) as carbon source was developed and is herein described. A simple two-stage precipitation procedure involving separation unit operations, pH and temperature manipulation and polishing through the removal of contaminants with activated carbon allowed the recovery of fumaric acid with 68.3% recovery yield with specifications meeting the requirements of the polymer industry. Further, process integration opportunities were implemented that allowed minimizing the generation of waste streams containing fumaric acid which enabled increasing the yield to 81.4% while keeping the product specifications.
Tue, 24 January 2017
ARTICLE Download: 813| View: 875| Comments: 0 | doi:10.20944/preprints201701.0105.v1
Subject: Life Sciences, Biotechnology Keywords: magnetic hyperthermia; gene therapies; heat shock protein promoter; in vivo optical imaging; magnetic polymer-coated nanoparticles
Online: 24 January 2017 (04:14:19 CET)
The present work aims to demonstrate that colloidal dispersions of magnetic iron oxide nanoparticles stabilized with dextran macromolecules placed in an alternating magnetic field can not only produce heat, but also that these particles could be used in vivo for local and non-invasive deposition of a thermal dose sufficient to trigger thermo-induced gene expression. Iron oxide nanoparticles were first characterized in vitro on a bio-inspired setup, and then they were assayed in vivo using a transgenic mouse strain expressing the luciferase reporter gene under transcriptional control of a thermosensitive promoter. Iron oxide nanoparticles dispersions were applied topically on the mouse skin or injected sub-cutaneously with Matrigel™ to generate so called pseudo tumors. Temperature was monitored continuously with a feedback loop to control the power of the magnetic field generator and to avoid overheating. Thermo-induced luciferase expression was followed by bioluminescence imaging 6 hours after heating. We showed that dextran-coated magnetic iron oxide nanoparticles dispersions were able to induce in vivo mild hyperthermia compatible with thermo-induced gene expression in surrounding tissues and without impairing cell viability. These data open new therapeutic perspectives for using mild magnetic hyperthermia as non-invasive modulation of tumor microenvironment by local thermo-induced gene expression or drug release.
Fri, 13 January 2017
ARTICLE Download: 797| View: 914| Comments: 0 | doi:10.20944/preprints201701.0071.v1
Subject: Life Sciences, Biotechnology Keywords: C-type lectin; agglutination; CRD; bacterial detection; E. coli
Online: 13 January 2017 (13:17:13 CET)
Lectins are carbohydrate-interacting proteins playing a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through the carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensor for capturing and identification of bacterial species. In this work, we have characterized the bacterial agglutination properties of three C-type lectins from the Lepidoptera Spodoptera exigua. One of these lectins, BLL2, was able to agglutinate cells from a broad range of bacterial species at an extremely low concentration, becoming a very interesting protein to be used as biosensor or other biotechnological applications involving bacterial capturing.
Wed, 9 November 2016
REVIEW Download: 988| View: 795| Comments: 0 | doi:10.20944/preprints201611.0055.v1
Subject: Life Sciences, Biotechnology Keywords: hybridization analysis; nucleic acids; optical biosensors; electrochemical biosensors; micromechanical (piezoelectric) sensors
Online: 9 November 2016 (10:28:58 CET)
In review, the operating principles of the most common bio sensing devices, detection methods and the identification sensitivity of analyzed molecules were shown. The central focus was done on hybridization analysis of nucleic acids (NA), which are considered to be one of the most important analytes in terms of diagnostic point of view. Constructions enabling to transfer the fact of formation of nucleotide probe/target complex in to detectable signal by optical, electrochemical or micromechanical (piezoelectric) sensors were presented in this review.
Mon, 26 September 2016
REVIEW Download: 2054| View: 905| Comments: 0 | doi:10.20944/preprints201609.0091.v1
Subject: Life Sciences, Biotechnology Keywords: biomaterial; scaffold; protein; keratin; tissue engineering
Online: 26 September 2016 (10:25:01 CEST)
In tissue engineering scaffolds take the place of the natural extra cellular matrix (ECM). The natural ECM is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The design aspect along with the choice of the material for the artificial scaffold is very crucial to cell differentiation, adhesion, proliferation, and the transport of the growth factors or other bio molecular signals. In addition to the material and design of the scaffolds, it is necessary to replicate the normal physiological situation if the scaffold has to function as an implant. The cells have to be located in the porous scaffold to form a three dimensional assembly. The article discusses the important factors to be considered while designing a scaffold for tissue engineering and regenerative medicine.
Mon, 8 August 2016
ARTICLE Download: 1203| View: 995| Comments: 0 | doi:10.20944/preprints201608.0072.v1
Subject: Life Sciences, Biotechnology Keywords: forest residue; pretreatment; liquefaction; enzymatic hydrolysis/saccharification; fermentation; high titer bioethanol; detoxification
Online: 8 August 2016 (10:39:56 CEST)
This study evaluated batch fermentation modes, namely, separate hydrolysis and fermentation (SHF), Quasi-simultaneous saccharification and fermentation (Q-SSF), and simultaneous saccharification and fermentation (SSF), and fermentation conditions, i.e., enzyme and yeast loadings, nutrient supplementation and sterilization, on high titer bioethanol production from SPORL-pretreated Douglas-fir forest residue without detoxification. The result indicated Q-SSF and SSF were obviously superior to SHF operation in terms of ethanol yield. The enzyme loading showed a strong positive correlation between enzyme loading and the ethanol yield. The nutrient supplementation and sterility was not necessary for ethanol production from SPORL-pretreated Douglas-fir. The yeast loading showed no significant influence on the ethanol yield for typical SSF conditions. The terminal ethanol titer of 43.2 g/L, or 75.1% theoretical based on glucose, mannose, and xylose theoretical was achieved when SSF was conducted at the condition of following: whole slurry solids loading of 15%, enzyme loading of 20 FPU/g glucan, 1.8 g/kg (wet) yeast loading, without nutrition supplementation and sterilization, at 38°C, on shake flask at 150 rpm for 96h. It is believed that with mechanical mixing, enzyme loading can be substantially reduced with affect ethanol yield by using a long fermentation time.