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Polysaccharide-degrading bacteria are key participants in the global carbon cycle and algal biomass recycling. Herein, a polysaccharide lyase-producing strain HB226069 was isolated from Sargassum sp. from Qingge Port, Hainan, China. Results of the phylogenetic of the 16S rRNA gene and genotypic analysis indicated that the isolate should be classified as Microbulbifer thermotolerans. The whole genome is a 4,021,337 bp circular chromosome with a G+C content of 56.5%. Analysis of the predicted genes indicated that strain HB226069 encoded 161 carbohydrate-active enzymes (CAZymes), and abundant putative enzymes involved in polysaccharide degradation were predicted, including alginate lyase, fucosidase, agarase, xylanase, cellulase, pectate lyase, amylase, and chitinase. Three of the putative polysaccharide lyases from PL7 and PL17 families were involved in alginate degradation. The alginate lyases of strain HB226069 showed the maximum activity of 117.4 U/mL at 50 °C, pH 7.0, and 0.05 M FeCl3, while exhibiting the best stability at 30 °C and pH 7.0. The Thin Layer Chromatography (TLC) and Electrospray Ionization Mass Spectrometry (ESI-MS) analyses indicated that the alginate oligosaccharides (AOSs) degraded by the partially purified alginate lyases contained oligosaccharides of DP2–DP5 and monosaccharide while reacting for 36 h. The complete genome of M. thermotolerans HB226069 enriches our understanding of the mechanism of polysaccharide lyase production and supports its potential application in polysaccharide degradation. [ABSTRACT FROM AUTHOR]

A strain designated Acinetobacter indicus WMB-7 with the ability to hydrolyze phthalate esters (PAEs) was isolated from the fermented grains of Baijiu. The genome of the strain was sequenced with a length of 3,256,420 bp and annotated with 3183 genes, of which 36 hydrolases encoding genes were identified. The hydrolases were analyzed by protein structure modeling and molecular docking, and 14 enzymes were docked to the ligand di-butyl phthalate with the catalytic active regions, and showed binding affinity. The 14 enzymes were expressed in E. coli and 5 of them showed the ability for PAEs hydrolysis. Enzyme GK020_RS15665 showed high efficiency for PAEs hydrolysis and could efficiently hydrolyze di-butyl phthalate under an initial concentration of 1000 mg/L with a half-life of 4.24 h. This work combined a series of methods for identifying PAEs hydrolases and offered a molecular basis for PAEs degradation of A. indicus strains from Baijiu. [ABSTRACT FROM AUTHOR]

Strain IB182493T, a marine, aerobic, Gram-stain-negative and motile bacterium, was isolated from seashore sand of South China Sea. Cells grew optimally at 25–30 °C, pH 7.0–8.0 and with 2–4% NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Paenibacillus, and was most closely related to Paenibacillus harenae DSM 16969 T (similarity 96.6%) and Paenibacillus alkaliterrae DSM 17040 T (similarity 96.1%). The chemotaxonomic characteristics of strain IB182493T included MK-7 as the predominant isoprenoid quinone, anteiso-C15:0 and iso-C16:0 as the major cellular fatty acids and meso-diaminopimelic acid as the diagnostic diaminoacid in cell wall peptidoglycan. The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and two unidentified phospholipids. The DNA G + C content of strain IB182493T was 56.2 %. The values of whole genome average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the isolate and the closely related type strains were less than 84.7% and 23.6%, respectively. On the basis of phenotypic and chemotaxonomic properties, phylogenetic distinctiveness and genomic data, we named the strain as Paenibacillus arenilitoris sp. nov. and proposed that strain IB182493T (= MCCC 1K04626T = JCM 34215 T) in the genus Paenibacillus represents a novel species. [ABSTRACT FROM AUTHOR]

A novel strain, designated BJN0001, was isolated from the cellar mud of Chinese strong-flavor baijiu. The complete genome of strain BJN0001 was 2,688,791 bp and annotated with 2610 genes. Whole-genome similarity metrics such as average nucleotide identity (ANI) of BJN0001 with reference genomes reveals clear species boundaries of < 95% ANI value for species. The DNA–DNA hybridization (DDH) values of BJN0001 with the type species were all lower than 70% DDH value for species. Based on these results, the strain BJN0001 was considered a potentially new species of the genus Clostridium. Meanwhile, the fermentation characteristics indicated that the strain had the capability to convert glucose to ethanol, acetic acid and butyric acid, which could provide basic data for revealing its function in baijiu fermentation. [ABSTRACT FROM AUTHOR]

Strain HA10002 was isolated from mangrove sediment collected from Dongzhaigang Mangrove Reserve in Hainan, China. It was selected with potent nematicidal activity and was identified as Streptomyces albogriseolus. By bioassay-guided fractionation, a new active component A22-1(S1) against root-knot nematodes was separated from its fermentation broth. On the basis of spectroscopic analyses and comparison with the data from correlative literature, the structure of S1 was established to be 6′-methyl-fungichromin, named as fungichromin B in this paper. The LD50 values of fungichromin B to the 2-stage juveniles of Meloidogyne incognita and Meloidogyne javanica were 7.64 and 7.83 μg/ml, respectively. Further examination demonstrated fungichromin B still showed a wide antifungal spectrum, as with fungichromin. [ABSTRACT FROM AUTHOR]

The coaxial electrospinning of two kinds of materials is one of the most popular fabrication methods to endow the composites with desirable properties. For the biodegradable and coaxial-electrospun poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) composite membranes, the effects of spinning parameters and the membrane density on the structure and mechanical property were still uncovered. In this work, biodegradable PLA and PBS composites were fabricated by means of coaxial-electrospinning followed by rolling press. The effects of PLA solution flow rate on the porous and crystal structure of the membrane were initially investigated. It was found that the pore size and porosity were independent on the flow rate. The crystallinity of PLA in the membrane increased with the increasing flow rate while that of PBS decreased, which brought about the composite membrane with enlarged tensile strength and reduced elongation. Then the influence of membrane density adjusted by the roller press was explored. Results showed that the porous structure greatly varied with the density. The larger the density was, the smaller the pore size and porosity were. Meanwhile, when the density was over 322 kg/m3, the tensile strength and elongation of the coaxial membrane were both higher than that of pure PLA and PBS, achieving the complementary effect of PBS and PLA on mechanical property. The investigation concentrated on the biodegradable PLA and PBS composites is beneficial to the composite materials with complementary properties for various applications. [ABSTRACT FROM AUTHOR]

Microbial community diversity and composition are important for the maintenance of mangrove ecosystem. Bacterial and archaeal community composition of the Bamenwan Mangrove Wetland soil in Hainan, China, was determined using pyrosequencing technique. Bacterial community composition presented differences among the five soil samples. Rhizobiales with higher abundance were observed in inner mangrove forest samples, while Desulfobacterales were in the seaward edge samples, and Frankiales, Gaiellales and Rhodospirillales in the landedge sample. For archaea, Crenarchaeota and Euryarchaeota dominated in five samples, but the proportion in each samples were different. Dominant archaeal community composition at the order level was similar in the seaward edge samples. The dominant archaeal clusters in the two inner mangrove forest samples were different, with Soil Crenarchaeotic Group (SCG) and Halobacteriales in sample inside of Bruguiera sexangula forest and SCG, Methanosarcinales and Marine Benthic Group B (MBGB) in sample inside of Xylocarpus mekongensis forest. The dominant archaeal clusters in land sample were unique, with Terrestrial Group and South African Gold Mine Group 1. The metabolic pathways including metabolism, genetic information processing, environmental information processing, cellular processes, organismal systems and human diseases were all detected for bacterial and archaeal functional profiles, but metabolic potentials among five samples were different. [ABSTRACT FROM AUTHOR]