Two new species of free-living nematode, Metachromadora parobscura sp. nov. and Molgolaimus longicaudatus sp. nov., from mangrove wetlands of Beihai, Guangxi province in China, are described. Metachromadora parobscura sp. nov. is characterized by eight longitudinal rows of somatic setae arranged from the posterior part of the body, loop-shaped amphidial foveae with an open top and double contours, pharynx with bipartite cuticularized internal cavity, spicules with well-developed capitulum, gubernaculum extended ventrally to support spicule, 6-8 precloacal tubular supplements, and short, conical tail with two protuberances. Molgolaimus longicaudatus sp. nov. is characterized by short cephalic setae, relatively small amphidial fovea, ventrally bent spicules with pronounced hamose curved proximal terminus, two undulate precloacal supplements, and relatively long conico-cylindrical tail. Nearly full-length SSU sequences of the two species were provided, and phylogenetic tree based on maximum likelihood analyses supported the taxonomic position of the two new species. Combined use of traditional morphology-based taxonomy and molecular technology would be a good choice for identification of free-living nematodes.

A solid structure, such as a road, building wall or envelop, used as a solar collector is considered an effective and new way to use renewable energy. This paper focused on the temperature characteristics of four structures exposed to sunshine: asphalt, red brick, composite cement and concrete road slab. Furthermore, the collected heat based on a hydraulic system was investigated experimentally. For the four structure slabs, their temperature differences are due to solar radiation absorption varied greatly by the material’s heat absorptance and color. Through the test, asphalt slab attained the highest temperature and had the weakest reflection among the structures. Compared with the others, the temperature of the asphalt slab was greater by 8.1%, 14.9% and 16.4% than the brick, composite cement and concrete, respectively. The reflection intensity growth ratio was defined and indicates the growth potential for absorbing radiation in the solid slab surface. From the experiments, it was concluded that a suitable selection of road materials can greatly improve the thermal absorption, conduction and penetration into the solid slab. The collected heat capability was approximately 250 W/m2 to 350 W/m2 in the natural summer condition. A black coating or a surface modification can collect more heat, reaching greater than 250 W/m2. The solar collecting heat efficiency with a surface configuration of the road slab can reach above 30% in the summer time.

Aborycin is a type I lasso peptide with a stable interlocked structure, offering a favorable framework for drug development. The aborycin biosynthetic gene cluster gul from marine sponge-associated Streptomyces sp. HNS054 was cloned and integrated into the chromosome of S. coelicolor hosts with different copies. The 3-copy gul-integration strains S. coelicolor M1346::3gul showed better production than one-copy or 2-copy gul-integration strains, and the total titer reached approximately 10.4 mg/L, i.e., 2.1 times that of the native strain. Then, five regulatory genes, phoU (SCO4228), wblA (SCO3579), SCO1712, orrA (SCO3008) and gntR (SCO1678), which were reported to have negative effects on secondary metabolism, were further knocked out from the M1346::3gul genome by CRISPR/Cas9 technology. While the ΔSCO1712 mutant showed a significant decrease (4.6 mg/L) and the ΔphoU mutant showed no significant improvement (12.1 mg/L) in aborycin production, the ΔwblA, ΔorrA and ΔgntR mutations significantly improved the aborycin titers to approximately 23.6 mg/L, 56.3 mg/L and 48.2 mg/L, respectively, which were among the highest heterologous yields for lasso peptides in both Escherichia coli systems and Streptomyces systems. Thus, this study provided important clues for future studies on enhancing antibiotic production in Streptomyces systems.