ARTICLE | doi:10.20944/preprints202112.0232.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Sweet potato; Phosphorus fertilizer; Bacillus megaterium DSM2894; leaf and tuberous root nutrients contents; Tuberous root yield
Online: 14 December 2021 (12:15:41 CET)
Under Egyptian soil conditions, when phosphorus fertilizers were applied to the soil, it gets fixed and converts to unavailable form, leading to low solubility for the plant. This study were fulfilled on sweet potato (cv. Beauregard) under undesirable soil properties (CaCO3 10.8 vs 11.3%) using Bacillus megaterium DSM 2894 strain under different five mono calcium phosphate (CSP) levels [(69(CSP20); 138(CSP40); 207 (CSP60); 276 (CSP80) and 345 ((CSP100) kg ha-1 of calcium superphosphate (CSP)] to arise the potential efficiency of some nutrients uptake and decease the applied total amount of CSP in 2019 and 2020 seasons. The results mentioned that highest values were obtained by inoculated plants with DSM2894 strain under 20, 60 and 100% of CSP for all studied nutrients content in both seasons, except Mn content in the 2019. Also, inoculated plants with DSM2894 under previous treatments for all tuberous root nutrients content, except Fe and Zn contents in both seasons, in addition protein and anti-radical power and total yield. Statistically, leaf nutrients uptake and tuberous root content were highly significant affected by DSM and CSP combination. Appling of phosphorus fertilizer with DSM2894 mixture was gave the best values as compared with phosphorus fertilizer or DSM2894, individually.
ARTICLE | doi:10.20944/preprints202104.0243.v1
Subject: Biology, Anatomy & Morphology Keywords: Oncorhynchus mykiss; Bacillus subtilis; Bacillus amyloliquefaciens; Lactobacillus 17 acidophilus; intestinal histology
Online: 8 April 2021 (14:04:05 CEST)
This paper studies the influence of three probiotic preparations of various microbiological composition: Bacillus subtilis (O1); Bacillus subtilis + Bacillus amyloliquefaciens (O2); Lactobacil-lus acidophilus (O3) on the growth process and histological structure of the organs of the gastroin-testinal tract of juvenile Oncorhynchus mykiss by morphometric parameters. The effect of the pro-biotic preparations led to the increase in fish growth and influenced different sections of the gastro-intestinal tract. The biggest change was found in the mid intestine and the reliable difference com-pared to the control was obtained at the following parameters: Lamina propria width, intraepithe-lial lymphocytes number of prismatic epithelium and goblet cells area. The changes in the pyloric appendages were less obvious but reported as playing an important functional role. The liver pre-served normal functional structure in all series of the experiment except for the probiotic group Lactobacillus acidophilus, where hepatocyte small-drop vacuolization was observed. That might be connected with the change of the digest activity resulting from a decrease in secretory activity of the intestinal exocrinocytes. The use of all the probiotic preparations led to the similar change in morphometric parameters, in all the groups it was possible to decrease the immune response.
Online: 31 August 2021 (11:41:51 CEST)
Bacillus anthracis, the causative agent of anthrax, has two virulence plasmids: pXO1 and pXO2. Plasmid pXO2 carries the genes of an antiphagocytic capsule synthesis. Plasmid pXO1 carries the genes pagA, lef, and cya encoding anthrax toxins, as well as atxA, which encodes the main regulator of pathogenicity factor expression. In the present paper, we evaluated the polymorphism of the pagA, lef, cya, and atxA genes for 85 B. anthracis strains belonging to different evolutionary lineages and canSNP groups and three B. cereus strains possessing pXO1-like plasmids. We found 19 genotypes (GT) strongly correlated with the main evolutionary lineages; they were mainly correlated with the canSNP group within these lines. In some cases, one GT combined the strains of several canSNP groups, and some canSNP groups were divided into several GTs. The most interesting of such cases were 1) the formation of a separate GT by strains of the A.Br.008/009 group isolated in the former USSR; 2) the presence of a unique GT in some American strains of the A.Br.Aust94 group; 3) the division of the A.Br.001/002 group into two subgroups, one of which may be a transitional link to the group A.Br.Ames; 4) the fact that European isolates of the B.Br.CNEVA group and Arctic strains of the B.Br.001/002 group have a common GT.
REVIEW | doi:10.20944/preprints201611.0087.v1
Online: 17 November 2016 (10:40:58 CET)
Oxidative stress occurs when cells are exposed to elevated levels of reactive oxygen species that could damage biological molecules. One bacterial response to oxidative stress involves disulfide bond formation either between protein thiols or between protein thiols and low-molecular-weight thiols. Bacillithiol was recently identified as a major low-molecular-weight thiol in Bacillus subtilis and related Firmicutes. Four genes (bshA, bshB1, bshB2 and bshC) are involved in bacillithiol biosynthesis. The bshA and bshB1 genes are part of a seven-gene operon (ypjD), which includes the essential gene cca, encoding CCA-tRNA nucleotidyltransferase. The inclusion of cca in the operon containing bacillithiol biosynthetic genes suggests that the integrity of the 3’ terminus of tRNAs may also be important in oxidative stress. Addition of the 3´ terminal CCA sequence by CCA-tRNA nucleotidyltransferase to give a mature tRNA and functional molecules ready for aminoacylation plays an essential role during translation and expression of the genetic code. Any defects in these processes, for example, the accumulation of shorter and defective tRNAs under oxidative stress, could exert a deleterious effect on cells. This review summarizes the physiological link between tRNACys regulation and oxidative stress in Bacillus.
SHORT NOTE | doi:10.20944/preprints202109.0241.v1
Subject: Life Sciences, Microbiology Keywords: Bacillus subtilis; bioemulsifier; enrichment; railway soil
Online: 14 September 2021 (12:58:40 CEST)
A novel enrichment combined with a rapid screening method was employed to isolate bioemulsifying strains of Bacillus subtilis. Among a total of twenty isolates from railway soil at six geographically distant sites, ten produced bioemulsifiers for soybean oil and crude oil. Qualitative drop-collapse assays indicated the bioemulsifiers were surfactants.
ARTICLE | doi:10.20944/preprints201808.0202.v1
Online: 10 August 2018 (05:45:08 CEST)
The optimum conditions for the fermentation of African locust bean (Parkia biglobosa) into a vegetable protein based condiment (Iru) were developed using Levenberg-Marquardt (or Powell) method (using PSI software) with three (3) variables namely; inoculum concentration (bacillus subtilis), temperature and the fermentation duration. African locust bean seeds were fermented at various temperature of 40 - 70 °С for five days (120 hours) with different concentrations of Inoculum. The proximate analysis shows that fermentation increased the percentage protein. Protein had the highest composition with about 51 % after 72 hours at the lowest fermentation temperature of 40°С.
ARTICLE | doi:10.20944/preprints202111.0426.v1
Subject: Life Sciences, Microbiology Keywords: Bacillus anthracis; anthrax; outbreak; phylogenetics; detection assay
Online: 23 November 2021 (14:44:33 CET)
The zoonotic disease anthrax caused by the endospore-forming bacterium Bacillus anthracis is very rare in Germany. In the state of Bavaria, the last case occurred in July of 2009 resulting in four dead cows. In August of 2021, the disease reemerged after heavy rains, killing one gestating cow. Notably, both outbreaks affected the same pasture, suggesting a close epidemiological connection. B. anthracis could be grown from blood culture and the presence of both virulence plasmids (pXO1 and pXO2) were confirmed by PCR. Also, recently developed diagnostic tools enabled rapid detection of B. anthracis cells and nucleic acids directly in clinical samples. The complete genome of the strain isolated from blood, designated BF-5, was DNA-sequenced and phylogenetically grouped within the B.Br.CNEVA clade that is typical for European B. anthracis strains. The genome was almost identical to BF-1, the isolate of 2009, separated only by three single nucleotide polymorphisms on the chromosome, one on plasmid pXO2 and three indel-regions. Further, B. anthracis DNA was detected by PCR from soil-samples taken from spots, where the cow had fallen onto the pasture. New tools based on phage receptor binding proteins enabled the microscopic detection and isolation of B. anthracis directly from soil-samples. These environmental isolates were genotyped and found to be SNP-identical to BF-1. Therefore, it seems that the BF-5 genotype is currently the prevalent one at the affected premises. The contaminated area was subsequently disinfected with formaldehyde.
ARTICLE | doi:10.20944/preprints201912.0344.v1
Subject: Biology, Other Keywords: Amylase; Bacillus; Soil bacteria; Antibiofilm; Pathogenic bacteria
Online: 25 December 2019 (09:48:15 CET)
Bacterial biofilms have become a significant and growing threat to human life, nature, and environmental health. The aim of this study is to isolate amylase-producing bacteria from the terrestrial environment (soil) for investigating their general inhibition of some pathogenic human bacterial biofilm. A total of 75 amylase producing isolates were obtained by serial dilution and streaking method. Amylotic activity of these isolates was screened by a starch agar plate method. Isolates were characterized by morphological and biochemical methods. The isolated Bacillus species were B. megaterium (26.7%), B. subtilis (16%), B. cereus (13.3%), B. thuringiesis (10.7%), B. lentus (10.7%), B. mycoides (5.3%), B. alvei (5.3%), B. polymyxa (4%), B. circulans (4%) and Micrococcus roseus (4%). The optimum conditions for amylase production were monitored. Antagonistic activity of these isolates and purified amylase against multidrug-resistant pathogenic human bacteria by agar disk diffusion method. The sensitivity level of some standard antibiotics served as control. Interestingly, it was found that all isolates exhibited great antagonistic activity against the target pathogens. The greatest activity recoded by B. alevi (48 mm) against Staphylococcus aureus (MRSA) and the lowest activity recorded by B. polymyxa (12 mm) against E. coli while low inhibition recorded for amylase. Antibiofilm efficacy of isolates supernatant and purified enzyme also monitored by spectrophotometric methods. The results revealed highly significant inhibition with percentages of 93.6 and 78.8% respectively. So, they represent a good tool for biofilm control in clinical and environmental applications.
ARTICLE | doi:10.20944/preprints202203.0320.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: biological control; anaerobically digested dairy slurry; Bacillus velezensis
Online: 24 March 2022 (02:25:19 CET)
This study was designed to assess the suppressive effects of various anaerobically digested slurries (ADSs), and the microorganisms inhabiting them, against Fusarium wilt in spinach. We used five different ADSs from a range of source materials (dairy cow manure, sewage sludge, food garbage, pig manure, night soil sludge), combined in different proportions. All five raw ADSs suppressed the growth of Fusarium oxysporum f. sp. spinaciae (Fos) on agar plates using a co-culture test. In contrast, filtrate ADSs did not suppress the growth of Fos. In total, 32 bacterial strains were isolated from five ADSs, and 8 isolates showed antagonistic activities against Fos. Based on 16S rDNA sequences, the strain AD-3 isolated from ADS from dairy cow manure belonged to Bacillus velezensis. Genome analysis revealed that AD-3 had two kinds of genes related to the production of the non-ribosomal lipopeptides, fengycin/plipastatin (pps genes), and surfactin (srf genes). In pot assays, inoculation of AD-3 (1.0 × 106 CFU·g−1 dry soil) into Fos-infected soil (1.0 × 105 bud-cells·g−1 dry soil) significantly reduced the severity of Fusarium wilt disease at 28 d after seedling. The percentage reductions in disease severity in two replicates were 64.3% and 44.3%, respectively. Thus, bacterial strain AD-3 could be applied to reduce Fusarium wilt in spinach.
ARTICLE | doi:10.20944/preprints202103.0134.v1
Subject: Biology, Anatomy & Morphology Keywords: Bacillus subtilis; NRPS/PKS; amicoumacins; heterologous expression; bioactivities
Online: 3 March 2021 (14:08:28 CET)
Abstract: Bacillus subtilis fmb60, which has broad-spectrum antimicrobial activities was isolated from plant straw compost. A hybrid NRPS/PKS cluster was screened from the genome. Sixteen secondary metabolites produced by the gene cluster were isolated and identified using LC-HRMS and NMR. Three lipoamides D–F (1-3) and two amicoumacin derivatives, amicoumacins D, E (4, 5), were identified, and are reported here for the first time. Lipoamides D–F exhibited strong antibacterial activities against harmful foodborne bacteria, with the MIC ranging from 6.25 to 25 µg/mL. Amicoumacin E scavenged 38.8% of ABTS+ radicals at 1 mg/mL. Direct cloning and heterologous expression of the NRPS/PKS and ace gene cluster identified its importance for the biosynthesis of amicoumacins. This study demonstrated that there is a high potential for biocontrol utilization of B. subtilis fmb60, and genome mining for clusters of secondary metabolites of B. subtilis fmb60 has revealed a greater biosynthetic potential for the production of novel natural products than previously anticipated.
ARTICLE | 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.
ARTICLE | doi:10.20944/preprints201806.0306.v1
Subject: Biology, Plant Sciences Keywords: Keywords: Bacillus amyloliquefaciens, Chitinase, Defense enzymes; Biological control
Online: 19 June 2018 (15:56:47 CEST)
To investigate whether the ech42 gene in Clonostachys rosea can improve the biocontrol efficacy of Bacillus amyloliquefaciens and its molecular mechanism.Compared to the wild type, the B. amyloliquefaciens transformed with the ech42 gene exhibited a higher chitinase activity. The B. amyloliquefaciens-ech42 also showed a significantly higher biocontrol efficiency against B. cinerea when tomato plants were pre-treated with amyloliquefaciens-ech42. No significant difference of control efficiency was observed between the wild type and amyloliquefaciens-ech42 when tomato plants were first infected by B. cinerea. In addition, the activity of the defense-related enzyme polyphenol oxidase, but not superoxide dismutase was significantly higher in amyloliquefaciens-ech42 than in the wild type.The ech42 enhances the Bacillus amyloliquefaciens biocontrol efficiency by increasing the capacity of protection/prevention to plants, rather treating/killing the pathogens.
ARTICLE | doi:10.20944/preprints201805.0084.v1
Subject: Biology, Animal Sciences & Zoology Keywords: Bacillus coagulans; intestinal function; gut microbiota; weaned piglet
Online: 4 May 2018 (05:31:44 CEST)
This research was to investigate beneficial impact and molecular mechanism of B. coagulans on piglets intestine. Twenty-four 21 days old weaned piglets were allotted to three treatments: control group (basal diet), B6 group (basal diet + 2×106 CFU/g B. coagulans), B7 group (basal diet + 2×107 CFU/g B. coagulans). The results showed that compared with control group, B6 and B7 group significantly decreased diarrhea rate and the concent of CHOL, GGT and DAO in plasma; decreased villus height and increase crypt depth in jejunum and ileum; increased the activities of SOD and CAT and decreased the concent of MDA and H2O2 in intestine. These data suggested that supplementing B. coagulans had beneficial impacts on promoting nutrients metabolism, maintaining intestinal integrity and alleviating oxidative stress and diarrhea. Futher research of molecular mechanisms showed that, these beneficial impacts were regulated by changing expression levels of related proteins (including HSP70, Caspase-3, Bax, Villin and Occludin), and genes (including RPL4, IFN-α, IFN-β, IFN-γ, MX1, MX2, OAS1, IL-1β, IL-4, CXCL-9, CCL-2, AQP3, SGLT-1, LPL, INSR and b0,+AT), and altering community composition of gut microbiota (particularly family Clostridiaceae, Enterobacteriaceae, and Veillonellaceae and genus Prevotella, Turicibacter, and Lactobacillus).
ARTICLE | doi:10.20944/preprints201801.0273.v2
Subject: Life Sciences, Microbiology Keywords: antagonism; Bacillus velezensis; Penicillium roqueforti; silage; roquefortine C
Online: 1 March 2018 (14:24:15 CET)
In Belgium, silages are often infected by Penicillium roqueforti sensu lato (s.l.). These toxigenic fungi are well adapted to silage conditions, and their prevention during feed-out is difficult. Bacillus velezensis strain NRRL B-23189 has been reported to inhibit P. roqueforti s.s. conidiospore germination in vitro by the production of lipopeptides. In the present study, the antagonistic effect of this B. velezensis strain towards P. roqueforti s.l. was evaluated in vitro and in vivo. In vitro, corn silage conditions were simulated, and the impact of B. velezensis culture supernatant or cell suspension on P. roqueforti s.l. growth, conidiospore germination and survival and roquefortine C production was evaluated. The antagonism was promising, but growth of B. velezensis in corn silage infusion was poor. An in vivo experiment with microsilos containing a mixture of perennial ryegrass and white clover artificially contaminated with P. roqueforti s.l. was carried out to determine if B. velezensis cell suspension could be used as an antagonistic silage inoculant. The B. velezensis cell suspension applied was unsuccessful in reducing P. roqueforti s.l. numbers at desiling after 56 days compared to no additive application. However, feed-out of the silage was not simulated, so it remains elusive whether or not B. velezensis exerts antagonistic activity during this phase.
ARTICLE | doi:10.20944/preprints201701.0096.v1
Subject: Earth Sciences, Geology Keywords: biomineralization; calcium ions; magnesium ions; Bacillus lichemiformis; carbonates
Online: 22 January 2017 (04:58:39 CET)
Reducing the hardness of hard water is of great concern nowadays due to some adverse effects on water pipes, boilers and soap consumption. Using the method of biomineralization to precipitate calcium and magnesium ions to become carbonate minerals was one of the most important innovations for reducing the hardness of hard water. The present study sought to explore the physical and chemical conditions of carbonates bio-precipitation and the potential use of Bacillus licheniformis SRB2 strain (GenBank: KM884945.1) isolated from sludge sample of Moshui River (Shandong University of Science and Technology, Qingdao, China) in reducing the hardness of hard waters by the induction of carbonate minerals. In this study, B. licheniformis SRB2 strain was identified based on the morphological, biochemical and 16S rDNA gene sequence homology analysis. The carbonate minerals induced by B. licheniformis bacteria in the liquid culture medium with 3% NaCl and Mg/Ca molar ratio of 0, 6, 8, 10 and 12 were investigated. The culture medium was inoculated with the bacterial liquid seed was set as the experimental group and the other culture medium was inoculated with the same volume of distilled water was set as the control group. The mineral phases, micromorphologies, and crystal structures were analyzed using X-ray powder diffraction, scanning electron microscope, energy dispersive X-ray detector, high resolution transmission electron microscopy and selected area electron diffraction. The bacterial concentrations and pH values of the solution were measured by a spectrophotometer and a pH meter, respectively. The urease secreted by B. licheniformis SRB2 was found to greatly increase the pH values of the liquid medium, which favored the formation of calcium carbonate.As a result, Mg2+ and Ca2+ ion concentrations decreased greatly due to the biomineralization of calcium carbonate and nesquehonite minerals in the presence of B. licheniformis SRB2 bacterium. There were only few calcium carbonates and no nesquehonite minerals in the control groups. It was also found that the minerals of nesquehonite induced by B. licheniformis SRB2 had a phenomenon of preferred orientation. What was more, even though Mg2+ ions inhibited the precipitation of Ca2+ ions, but under the action of B. licheniformis SRB2 bacteria, the inhibition effect was significantly declined. The bio-precipitation of calcium carbonate and nesquehonite minerals may represent a new method of pretreatment for the hardness reduction of hard water. The accomplished study is of certain interest for interpretation of the carbonates biomineralization in natural environment, and maybe also has a certain application value in the former processing of hard water
REVIEW | doi:10.20944/preprints202112.0433.v1
Subject: Life Sciences, Microbiology Keywords: Lactobacillus spp, Bacillus spp., Anti-cancer, Probiotics, Gastrointestinal, Dysbiosis.
Online: 27 December 2021 (14:50:58 CET)
Malignant neoplasm is one of the most incurable diseases among inflammatory diseases. Researchers have been studying for decades to win over this lethal disease and provide the light of hope to humankind. The gastrointestinal bacteria of human hold a complex ecosystem and maintain homeostasis. One hundred trillion microbes are residing in the gastrointestinal tract of human. Disturbances in the microbiota of human’s gastrointestinal tract can create immune response against inflammation and also can develop diseases , including cancer. The bacteria of the gastrointestinal tract of human, can secrete a variety of metabolites and bioproducts which aid in the preservation of homeostasis in the host and gut. During pathogenic dysbiosis, on the other hand, numerous microbiota subpopulations may increase and create excessive levels of toxins, which can cause inflammation and cancer. Furthermore, the immune system of host and the epithelium cell can be influenced by gut microbiota. Probiotics, which are bacteria that live in the gut, have been protected against tumor formation. Probiotics are now studied to see if they can help fight dysbiosis in cancer patients undergoing chemotherapy or radiotherapy because of their capacity to maintain gut homeostasis. Countless numbers of gut bacteria have demonstrated anti-cancer efficiency in cancer treatment, prevention, and boosting the efficiency of immunotherapy. The review article has briefly explained the anti-cancer immunity of gut microbes and their application in treating a variety of cancer. This review paper also highlights the pre-clinical studies of probiotics against cancer and the completed and ongoing clinical trials on cancers with the two most common and highly effective probiotics Lactobacillus and Bacillus spp.
ARTICLE | doi:10.20944/preprints202101.0531.v2
Subject: Life Sciences, Biochemistry Keywords: Priming; RNAi; Tribolium castaneum; Host-parasite interaction; Bacillus thuringiensis
Online: 13 April 2021 (10:29:30 CEST)
Insects possess an array of defense molecules allowing them to fight infections. They can also show a form of immune memory, named priming. However, the involvement of insect immune defense mechanisms in priming is unclear, since invertebrates lack the molecular machinery present in vertebrates to build an immune memory. In the red flour beetle Tribolium castaneum, larvae can be primed via the oral route with Bacillus thurigiensis var. tenebrionids (Btt). This results in changes in the expression of a large number of genes, among which some belong to families of ancient defense genes. In the present work, we tested whether three chosen candidate genes (a Thaumatin, a C-type Lectin and an Osiris-like gene) could be involved in the survival to a Btt exposure, as well as in the priming phenotype. We assessed changes in their expression over time and according to the priming treatment, knocked them down individually by RNA interference (RNAi), and observed how it affected survival upon challenge. The quantification of gene expression patterns in our larvae with RT-qPCR showed that up- and/or down-regulation of the genes, after the priming treatment, was quite volatile and time dependent. Upon knock-down, we did not observe the expected decrease in survival to Btt or the abolishment of the priming phenotype. We conclude that knocking down genes individually is probably insufficient to affect survival and priming in our system. This gives us insight into the complexity of the molecular processes underpinning priming.
ARTICLE | doi:10.20944/preprints202103.0480.v1
Subject: Life Sciences, Biochemistry Keywords: Amylase; Bacillus sp. H7; Optimization; Production; Response surface method
Online: 18 March 2021 (12:22:42 CET)
Using the above results from RMS analysis the optimum values were predicted for the independent significant variables (Figure 3) the optimized levels of these variables in combination with other media variables the maximum production was predicted to be 199.90 U/mL. The predicted data were validated through confirmatory experiments performed in triplicates. A 1.29-fold increase in amylase activity against un-optimized (OVAT) medium was achieved in the present study authenticating the efficacy of RSM in process optimization (Figure 4). 2.6 Model validation and scale-up at laboratory scale (5L) bioreactor Once the parameters were standardized in the shake-flasks culture, the experiment was scaled-up to a laboratory-scale bioreactor (5 L). The yield of amylase increased by 1.01 fold (205.69 U/mL), it could be possible because the enzyme production in a bioreactor is higher than in shake-flasks culture as the various critical variable factors such as the dissolved oxygen (DO) and the pH can be optimally controlled at the desired levels .
ARTICLE | doi:10.20944/preprints202010.0570.v1
Subject: Biology, Anatomy & Morphology Keywords: Mosquito vector; biological control; Bacillus thuringiensis; ovillanta; Bti; biolarvicide
Online: 28 October 2020 (08:34:44 CET)
The bacterial genus and species of Bacillus thuringiensis var israelensis (Bti), is entomotoxic, used in the biological control of mosquito vectors of human diseases, such as malaria and dengue. Following the studies carried out in Mexico and Guatemala with ovillantas, in which the presence of larvae of both species of Anopheles albimanus W and Aedes aegypti L were observed, and with the intention of continuing to develop an ecologically friendly mosquito control, Bti was added to the ovillantas, to improve and already efficient method on the elimination of both types of mosquitoes. The objectives of this work were: to analyze the effectiveness of two commercial formulations of Bti, serovar H-14 (Bactimos) wettable powder, 3,500 ITU, from Biochem prods., and Vectobac, 2,000 ITU wettable powder, (Abbot Lab.) on second and third instars larvae of A. albimanus and Ae. aegypti (Diptera Culicidae). The two formulations were effective against A. albimanus W(higher concentrations), while Ae. aegypti L was very susceptible to Bti, therefore it is proposed for the best control of these genus and vector species of malaria and dengue at adequate concentrations.
ARTICLE | doi:10.20944/preprints202008.0486.v1
Subject: Life Sciences, Microbiology Keywords: Bacillus subtilis; Bio-surfactants; emulsification index; Hydrocarbons; surface tension.
Online: 21 August 2020 (13:27:24 CEST)
Bio-surfactants are surface-active molecules which are produced by the wide range of microbes including bacteria, fungi, and yeast. This study was conducted to identify bio-surfactants by Bacillus subtilis combined with use of cheap substrates and industrial wastes (Mustard cake, Whey and Soya cake) which are found locally in Nepal. Bacillus subtilis, one of the most potential bio-surfactants producer; was isolated from soil sample of hydrocarbon contaminated site. Isolates were grown in a Minimal Salt Media (MSM) with 10% (v/v) mustard oil cake, whey and soya cake separately. The presence and potential of surfactant was determined by the oil spreading technique, emulsification index (%E24) and surface tension measurement. It was revealed that the surface tensions of cell free extract were 54.41, 60.02 and 56.64 mN/m for from mustard cake, whey and soya cake respectively as compared to distilled water (72.09) at 25oC. The emulsification index values are was found to be highest in engine oil from the bio-surfactant extracted from mustard cake, soya cake and whey respectively. Similarly, mustard oil showed the lowest value of emulsification index. The highest emulsification activity was shown in mustard oil i.e. 1.13 from the cell free extract from mustard oil and lowest in engine oil i.e., 0.07, by the extract from soya cake medium, when measured in spectrophotometer at 540 nm. In conclusion, strain of Bacillus subtilis was found to be the potential surface active agent producers on the mustard oil cake, which can be useful medium for various environmental, food and industrial processes.
ARTICLE | doi:10.20944/preprints202107.0130.v1
Subject: Biology, Anatomy & Morphology Keywords: Arbutus unedo; Bacillus cereus; Bacteria endophytes; Biological control; Phytophthora cinnamomi
Online: 6 July 2021 (09:42:41 CEST)
Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary and bacteria endophytes may increase their host overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing on orchards. 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Also, several endophytic isolates exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth-promoters and pathogen antagonists.
REVIEW | doi:10.20944/preprints202103.0075.v1
Subject: Life Sciences, Biochemistry Keywords: Probiotics; Bacillus subtilis; growth performance; immune-hematological parameters; stress resistance
Online: 2 March 2021 (11:06:52 CET)
Aquaculture is one of the fastest-growing animal food-producing agricultural industries in the world and proper performance of fish in morphological, physiological and immunological aspects is important for fish production and sustainable expansion of aquaculture. But several inhibitors like disease, pathogen, and adverse environment can overpower these performances. At present, antibiotics in preventing these inhibitors have been seen as becoming favorable to those inhibitors. So, Bacillus, an important group of probiotic bacteria can be an alternative to these antibiotics in aquaculture. Bacillus has been seen used in different experiments, mainly as a supplement in feed at various concentrations. Bacillus showed effective results like improved growth with minimum cost, improvement in reproduction, hematology, improved immune response and disease, and stress resistance as well as better proximate composition in different fish species. Application of Bacillus strains has proven efficient in improving water quality by reducing ammonia and nitrite toxicity, harmful algal blooms and utilization of H+ ion. Larger application of probiotic Bacillus instead of the hazardous synthetic chemicals would promote eco-friendly low-input sustainable aquaculture for food and nutritional security of the increasing world population. So many more experiments should be conducted in commercially important fishes for better growth and health of fishes which will certainly increase fish
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: laying hen; social stress; injurious behavior; microbiota; probiotic; bacillus subtilis
Online: 17 January 2020 (12:37:53 CET)
Some management practices, such as maintaining birds under high group density, used in the poultry industry may cause birds stress, leading to injurious behaviors, such as injurious pecking, aggression, and cannibalism. In addition, some management practices used to prevent severe injuries in birds may cause pain. Beak trimming (BT), removal of 1/3 to 1/2 of a beak, is a routine husbandry procedure practiced in laying hens to prevent or reduce injurious behaviors. However, BT causes tissue damage, which may increase somatosensory sensitization of the damaged nerve tissues, resulting in pain (acute, chronic or both) in the treated birds because the beak is a complex, functional organ with an extensive nerve supply. BT has already been heavily regulated or prohibited in several European countries and, in time, this trend will impact the practice used in the United States poultry industry. With the growing public concern for poultry welfare there is a pressing need to identify and develop alternatives to BT. Probiotics defined “as a source of live (viable) naturally occurring microorganisms (direct-fed microbials)” have been used as dietary supplements or functional foods to target gut microbiota (microbiome) for prevention or therapeutic treatment of mental diseases including social stress-induced psychiatric disorders in humans and various experimental animals. In our studies, chickens were used as an animal model to assess if dietary supplementation of probiotic, Bacillus subtilis, reduces injurious behaviors following social challenge. Hens of Dekalb XL strain, an aggressive line, were used in the studies. Our results indicate that dietary supplementation of the Bacillus subtilis based probiotic reduces aggressive behaviors in chickens. These results suggest dietary probiotics could be a suitable strategy for increasing hosts’ health status and welfare conditions.
ARTICLE | 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.
ARTICLE | doi:10.20944/preprints201703.0018.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Cicer arietimum; Indole Acetic Acid; Bacillus megaterium; Pseudomonas putida; Mesorhizobium ciceri
Online: 2 March 2017 (16:34:44 CET)
Six bacterial strains with differing abilities to produce varying concentrations of Indole Acetic Acid were tested individually and in consortia for plant growth promoting and fitness related traits of Cicer arietinum. In all experiments the presence of the nitrogen fixer Mesorhizobium ciceri resulted in increased biomass production. In the absence of this strain, IAA Psedomonas putida and Bacillus megaterium hinder plant growth and fitness related traits. The application of mixes of the three strains always resulted in better plant performance when M. ciceri was present. Whereas P. putida has a noticeable plant growth-promoting effect B. megaterium resulted less effective. The low levels of IAA produced by the selected strains had a significantly greater positive effect on plant biomass accumulation, flower, pods and seed production as well as on total plant nitrogen and nitrogen concentration in seed than high IAA producer strains.
ARTICLE | doi:10.20944/preprints202004.0072.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Bacillus pumilus HY1; solid-state fermentation; cheonggukjang; surfactin; mass spectrum; anticancer effect
Online: 7 April 2020 (00:54:39 CEST)
The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1,008.7, 1022.7, 1036.7, and 1,050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The surfactin extraction of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 μg/μL surfactin. These results suggest that surfactins produced from strain HY1 have anticancer properties.
ARTICLE | doi:10.20944/preprints201912.0335.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Bacillus cereus; mild heating; dielectric barrier discharge plasma; red pepper powder; quality
Online: 25 December 2019 (03:46:00 CET)
The synergistic efficacy of combined treatment mild heat (MH) and dielectric barrier discharge (DBD) plasma in Bacillus cereus-contaminated red pepper powder was tested. A cocktail of three strains of B. cereus (NCCP 10623, NCCP 14579, ATCC 11778) was inoculated onto red pepper powder and then treated with MH (60 ℃ for 5-20 min) and DBD plasma (5-20 min). Treatment with MH and DBD plasma alone for 5~20 min resulted in reductions of 0.23~1.43 and 0.12~0.96 log CFU/g, respectively. Combined treatment with MH and DBD plasma was the most effective at reducing B. cereus counts on red pepper powder and resulted in log-reductions of ≥ 6.0 log CFU/g. The largest synergistic values (4.24-4.42 log) against B. cereus in red pepper powder were obtained by the combination of 20 min MH and 5~15 min DBD plasma. Hunter color ‘‘L’’, ‘‘a’’, and ‘‘b’’ values of the combination-treated samples were not significantly different from those of non-treated samples. Also, no significant (p > 0.05) differences in pH values between samples were observed. Therefore, these results suggest that the combination of MH treatment and DBD plasma can be potentially utilized in the food industry to effectively inactivate B. cereus without incurring quality deterioration of red pepper powder.
ARTICLE | doi:10.20944/preprints201810.0267.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Mg/Ca; biominerliazation; nucleation site; Bacillus licheniformis DB1-9; carbonic anhydrase; ammonia
Online: 12 October 2018 (11:56:44 CEST)
Biomineralization has become a research hotspot and attracted widespread attention in the field of carbonate sedimentology. In this study, Bacillus licheniformis DB1-9 was used to induce the calcium carbonate precipitation at different magnesium calcium molar ratios in the laboratory to further explore the biomineralization mechanism. Phylogenetic tree shows that the bacteria belongs to Bacillus licheniformis species. The ammonia and carbonic anhydrase can be released by this bacteria, resulting in the pH increase, and the carbonic anhydrase can also promote the hydration reaction of carbon dioxide and subsequently produce the bicarbonate and carbonate ions to elevate the supersaturation of calcium carbonate in the liquid culture medium to facilitate the precipitation of carbonate minerals. The calcites have a shape of rhombohedron, dumbell, and elongation, and aragonite often appears in the form of mineral aggregates, besides that there are also the spherical and the fusiform minerals. FTIR result shows there are some organic functional groups, such as C-O-C and C=O, beside of the characteristic peaks of the calcite and the aragonite, indicating that microbial metabolism is closely related to the mineral formation. The superthin slices of the bacteria analyzed by HRTEM, SAED, EDS and STEM show that the surface and EPS can adsorb a large number of calcium ions and magnesium ions and EPS may act as the nucleation sites, what’s more, the intracellular nanometer-scale sphere areas show the amorphous structures, and the intracellular calcium ions and magnesium ions suggeste that they can be transported from the outside to inside the cell by diffusion along the concentration grade from high to low. This study may provide some references to further understand the biomineralization mechanism induced by microorganisms in the laboratory and the field, and also helps to explore the reason of the transition of calcite sea to aragonite sea in the geological history.
ARTICLE | doi:10.20944/preprints202111.0304.v1
Subject: Biology, Other Keywords: amino acid permease; L-aspartic acid; Bacillus licheniformis; whole-cell biocatalyst; fermentation engineering
Online: 17 November 2021 (11:58:31 CET)
Amino acid efflux and influx transport systems play vital roles in industrial microorganisms’ cell growth and metabolism. However, although biochemically characterized, most amino acid transporters remain unknown at the molecular level in Bacillus licheniformis. This study focuses on the molecular and functional characterizations of three transporters, YdgF, YvbW, and YveA, mainly when catalyzing the cross-membrane flux of L-Aspartate. When growing in the minimal medium with L-Asp as the only carbon and nitrogen source, the growth of strains lacking proteins YdgF, YvbW, and YveA was significantly inhibited compared with wild-type strains, while supplementing the expression of the corresponding proteins in the single-gene knockout strains can alleviate the inhibition to some extent. Upon overexpression, the recombinant proteins mediate the accumulation of L-aspartate to varying degrees. Compared with wild-type strains, the single knockout strains of the three protein genes exhibited reduced absorption of L-aspartate. In addition, this paper focuses on the effects of these three proteins on the absorption of β-alanine, L-glutamate, D-serine, D-alanine, and glycine.
REVIEW | doi:10.20944/preprints202206.0402.v1
Subject: Biology, Other Keywords: Bacillus nattokinase; Physiological and biochemical characteristics; Molecular structure; Molecular modifcation; Functional food and clinical application
Online: 29 June 2022 (09:39:07 CEST)
Thrombosis has threatened human health in past decades. Bacillus nattokinase is a potential thrombolytic drug without side-effect and low cost and has been introduced into the consumer market as a functional food or dietary supplement. This review firstly summarizes the biodiversity sources and fermentation process of nattokinase, and systematically expounds the structure, cata-lytic mechanism and enzymatic properties of nattokinase; In view of the problems of low fermen-tation yield, insufficient activity and stability of nattokinase, this review discusses the heterologous expression of nattokinase in different microbial hosts, and summarizes the protein and genetic en-gineering progress of nattokinase-producing strains; Finally, this review summarizes the clinical application of nattokinase.
ARTICLE | doi:10.20944/preprints202012.0784.v1
Subject: Life Sciences, Biochemistry Keywords: Bacillus subtilis; flow cytometry; gastrointestinal health; peripheral blood mononuclear cells (PBMC); probiotic; short chain fatty acid
Online: 31 December 2020 (09:46:43 CET)
Probiotics make up a large and growing segment of the commercial market of dietary supplements and are touted as offering a variety of human health benefits. Some of the purported positive impacts of probiotics include, but are not limited to, stabilization of the gut microbiota, prevention of gastrointestinal disorders and modulation of the host immune system. Current research suggests that the immunomodulatory effects of probiotics are strain specific and vary in mode of action. Here, we examined the immunomodulatory properties of Bacillus subtilis strain DE111 in a healthy human population. In a randomized, double blind, placebo-controlled four-week intervention, we examined peripheral blood mononuclear cells (PBMCs) at basal levels pre- and post-treatment as well as in response to stimulation with bacterial lipopolysaccharide (LPS). We observed an anti-inflammatory effect of B. subtilis, manifested as a decrease in immune cell populations within the basal state along with an increase in anti-inflammatory immune cells in response to LPS stimulation. Overall gastrointestinal health, microbiota, and circulating and fecal markers of inflammation and gut barrier function were largely unaffected by DE111 treatment. These data suggest that the novel probiotic B. subtilis DE111 may have clinical applications in modulating immune homeostasis via anti-inflammatory mechanisms.
ARTICLE | doi:10.20944/preprints201904.0303.v1
Subject: Biology, Other Keywords: selective biomineralization; recovery of Au(III); AuNP; bacillus licheniformis FZUL-63; aqua regia-based metal wastewater
Online: 28 April 2019 (08:36:49 CEST)
The recovery of precious metals is a project with both economic and environmental significance. In this paper, it presents how to use bacterial mineralization to selectively recover gold from multi-ionic aqueous systems. The Bacillus licheniformis FZUL-63, separated from a landscape lake in FuZhou University, was shown to selectively mineralize and precipitate gold from coexisting ions in aqueous solution. The removal of Au(III) was almost happened in first hour, and FTIR data show that the amino, carboxyl and phosphate groups on the surface of the bacteria are related to the adsorption of gold ions. XPS results implied that Au(III) ions are reduced to monovalent, and then the Au(I) was adsorbed on the bacterial surface at the beginning stage(first hour). XRD results showed the gold biomineralization began about 10 hours after the interaction between Au(III) ions and bacteria. The Au(III) mineralization has been rarely influenced by other co-existing metal ions. TEM analysis shows the gold nanoparticles are polyhedral structure with a particle size of ~20 nm. The Bacillus licheniformis FZUL-63 could selectively mineralize and recover 478 mg/g(dry biomass) gold from aqua regia-based metal wastewater through four cycles. It could be of great potential in the practical application.
ARTICLE | doi:10.20944/preprints202102.0241.v1
Subject: Biology, Anatomy & Morphology Keywords: plant-growth-promoting bacteria; spore-forming bacteria; Bacillus vallismortis; Macrophomina phaseolina; phenotypic and genotypic characterization; Biocontrol agents
Online: 9 February 2021 (15:09:32 CET)
In the last decades, intensive crop management has involved excessive use of pesticides or fertilizers, compromising environmental integrity and public health. Accordingly, there has been worldwide pressure to find an eco-friendly and safe strategy to ensure agricultural productivity. Recently, Plant Growth-Promoting (PGP) rhizobacteria are receiving increasing attention as suitable biocontrol agents against agricultural pests. In the present study, 22 spore-forming bacteria were selected among a salt-pan rhizobacteria collection for their PGP traits and their antagonistic activity against the plant pathogen fungus Macrophomina phaseolina. Based on the higher antifungal activity, strain RHFS10, identified as Bacillus vallismortis, was furtherly examined and cell-free supernatants assays, column purification, and tandem mass spectrometry employed to purify and preliminarily identify the antifungal metabolites. Interestingly, the minimum inhibitory concentration assessed for the fractions active against M. phaseolina, resulted 10 times lower and more stable than the one estimated for the commercial fungicide pentachloronitrobenzene. These results suggest the use of B. vallismortis strain RHFS10 as a potential Plant Growth Promoting Rhizobacteria to efficiently control phytopathogenic fungus M. phaseolina, in alternative to chemical pesticides.
ARTICLE | doi:10.20944/preprints201811.0458.v1
Subject: Life Sciences, Microbiology Keywords: Bacillus; Bioremediation; Enzymes; Fourier transformed infrared spectroscopy (FTIR); Gas chromatography-mass spectrometry (GC-MS); Physicochemicals; Textile wastewater.
Online: 19 November 2018 (11:19:08 CET)
The present study evaluates the bioremediation potential of indigenous bacterial species isolated from dye-contaminated soil samples from small dyeing outlet located in Ilorin. The water pollution index was estimated based on the physicochemical characteristics and heavy metal concentrations of the raw (Day 0) and treated textile wastewater such as pH, biochemical oxygen demand-5, chemical oxygen demand, total suspended solids and total dissolved solid with mean values of 8.85±0.45 mg/L, 1200±21.3 mg/L, 2440±31.3 mg/L, 1660±17.2 mg/L and 2650±28.1 mg/L respectively, similarly, Lead was the most abundant heavy metal detected in the sample while Cadmium concentration was the lowest with the mean values of 3.52±0.00 mg/L and 2.18±0.00 mg/L respectively. The bacterial strain with highest dye decolorization capacity was screened and identified as Bacillus licheniformis ZUL012.The isolate was consequently used for the bioremediation of the wastewater over a period of 10 days. The results showed an incredible reduction in the physiochemical characteristics and heavy metal concentrations of the textile wastewater in the following ranges (8.85-6.55), (1200-300) mg/L, (2440-518) mg/L, (1660-666) mg/L and (2650-920) mg/L with the highest removal efficiency of 75 %, 78 %, 60%, 65%, recorded for biochemical oxygen demand, chemical oxygen demand, total suspended solid, total dissolved solid, respectively while that of heavy metals such as lead, cadmium, chromium and nickel were 80 %, 60 %, 67 %, 72 % reduction, respectively. Laccase and Azoreductase activities tend to decrease as the pH gradually moved towards acidic condition during the bioremediation process. Toxicity of the treated effluent was assessed using Maize and Bean seed germination test. Conclusively, these research findings can serve as a framework for the outlet design of wastewater treatment plant for local textile outlets.
ARTICLE | doi:10.20944/preprints202208.0150.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: black pepper; Bacillus veleznesis; root-knot nematodes; antinematodes compounds; organic wastes; microbial fermentation; thymine; hexahydropyrrolo [1,2-a]pyrazine-1,4-dione
Online: 8 August 2022 (10:30:28 CEST)
Bacillus veleznesis RB.EK7 was recently found as a potent rhizobacterial strain for effective management of black pepper root-knot nematodes. This work aimed to produce, purify, and elucidate the chemical structures of antinematode compounds (ANCs). Concerning cost-effectiveness and environmental issues, this study used organic wastes for the bioproduction of ANCs. Among various substrates, shrimp shells powder was the most suitable carbon/nitrogen source to produce ANCs. The fermentation process for enhancement of antinematode activity was investigated. The targeting ANCs were purified from the fermented culture broth, and their structures were elucidated. Two active compounds were thymine (1) and hexahydropyrrolo [1,2-a]pyrazine-1,4-dione (2). Notably, for the first time, these purified compounds showed potential and moderate anti- J2 nematodes and anti-eggs hatching, respectively. The docking study results indicated that the potent antinematode effect of these compounds may be possibly due to the inhibition of the targeting enzyme acetylcholinesterase. The data of this work suggest that organic waste SSP can be potentially reused for the production of thymine and hexahydropyrrolo [1,2-a] pyrazine-1,4-dione with promising use for the management of black pepper nematodes.
HYPOTHESIS | doi:10.20944/preprints202010.0199.v1
Subject: Life Sciences, Biochemistry Keywords: CRISPR interference; error-prone polymerase chain reaction; ribosomal proteins; ribosome; viability assay; Bacillus subtilis; Escherichia coli; sequence space; conformational space; mutational map
Online: 9 October 2020 (12:24:14 CEST)
Ribosomes are macromolecular complexes important to protein translation, and thus, essential to life. Comprising an ensemble of ribosomal proteins and RNA molecules, ribosomes are conserved in structure and function across all domains of life, but recent structural studies have revealed differentiated structures of ribosomes from bacterial, archaea and eukaryotes. Additionally, unique ribosomal protein mass fingerprints have been found for individual species; thereby, indicating that ribosomes are differentiated in structure amongst different species. Given that structure defines function, differentiated function likely exists amongst ribosomes of different species, which could manifest as differences in translation efficiency that could impact on cell growth rate. But ribosomal proteins also hold phylogenetic significance in informing the evolutionary trajectory of each species. Such ribosomal proteins are thus not highly conserved and offers sufficient sequence space for the evolution of differentiated structure and function in different species. Using ribosomal proteins that hold phylogenetic significance as templates, this study sought to understand the mutational and conformational limits that define functional ribosomes. Specifically, ribosomal proteins in Bacillus subtilis that hold phylogenetic cues would be mutated through error-prone polymerase chain reaction to generate variants that are subsequently transformed into Escherichia coli. To help assess the functional properties of the heterologous ribosomal proteins, endogenous ribosomal protein genes would be inactivated by multiplex CRISPR interference. Since variants in ribosomal proteins would likely impact on ribosome function and translation efficiency, live/dead screening on LB agar would be effective as a preliminary screen for functional mutants. These mutants would subsequently be inoculated into liquid LB medium in 96 well plates to quantify relative growth rates between different strains harbouring different heterologous variants of ribosomal proteins. Plasmids containing different ribosomal protein mutants would be extracted from each functional strain and subjected to Sanger sequencing for determining the specific mutations involved. Collection of such mutations would provide a comprehensive mutational map that define the limits of ribosomal protein sequence space important to ribosome function. Furthermore, biochemical isolation of ribosomal proteins and their structural characterization by X-ray crystallography or cryo-electron microscopy would further illuminate the structural significance of each mutation on ribosome structure and function; thereby, elucidating the structural tolerance space for functional ribosomes. Overall, generating a diverse pool of mutant ribosomal proteins in viability assays followed by sequencing and structural characterization would help define the mutational and conformational limits of a functional and efficient ribosome.
REVIEW | doi:10.20944/preprints202209.0139.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Bacillus Calmette-Guérin (BCG); tuberculosis; Non-tuberculous mycobacteria (NTM); nonspecific effects; Trained Immunity; Type 1 Diabetes; Multiple Sclerosis; Parkinson’s Disease; Alzheimer’s disease; Mycobacterium avium ss. paratuberculosis (MAP); molecular mimicry; Global Burden of Disease
Online: 12 September 2022 (09:36:16 CEST)
The Bacillus Calmette-Guérin (BCG) vaccine has been used for over one hundred years to protect against the most lethal infectious agent in human history, tuberculosis. Over four billion BCG doses have been given and, worldwide, most newborns receive BCG. A few countries, including the United States, did not adopt the WHO recommendation for routine use of BCG. Moreover, within the past several decades, most of Western Europe and Australia, having originally employed routine BCG, have discontinued its use. This review article articulates the impacts of those decisions. The associated consequences include increased tuberculosis, increased infections caused by non-tuberculous mycobacteria (NTM), increased autoimmune disease (autoimmune diabetes and multiple sclerosis) and increased neurodegenerative disease (Parkinson’s disease and Alzheimer’s disease). This review also offers an emerged zoonotic pathogen, Mycobacterium avium ss. paratuberculosis (MAP) as a mostly unrecognized NTM that may have a causal role in some, if not all, of these diseases. Current clinical trials with BCG for varied infectious, autoimmune and neurodegenerative diseases have brought this century-old vaccine to the fore due to its presumed immuno-modulating capacity. With its historic success and strong safety profile, the new and novel applications for BCG may lead to its universal use –putting the Western World back onto the road not taken.