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Petroleum-hydrocarbon-degrading bacteria were obtained after enrichment on crude oil (as a 'chocolate mousse') in a continuous supply of Indonesian seawater amended with nitrogen, phosphorus and iron nutrients. They were related to Alcanivorax and Marinobacter strains, which are ubiquitous petroleum-hydrocarbon-degrading bacteria in marine environments, and to Qceanobacter kriegii (96.4-96.5% similarities in almost full-length 16S rRNA gene sequences). The Oceanobacter-related bacteria showed high n-alkane-degrading activity, comparable to that of Alcanivorax borkumensis strain SK2. On the other hand, Alcanivorax strains exhibited high activity for branched-alkane degradation and thus could be key bacteria for branched-alkane biodegradation in tropical seas. Oceanobacter-related bacteria became most dominant in microcosms that simulated a crude oil spill event with Indonesian seawater. The dominance was observed in microcosms that were unamended or amended with fertilizer, suggesting that the Oceanobacter-related strains could become dominant in the natural tropical marine environment after an accidental oil spill, and would continue to dominate in the environment after biostimulation. These results suggest that Oceanobacter-related bacteria could be major degraders of petroleum n-alkanes spilt in the tropical sea. DOI 10.1099/mic.0.030411-0

Research has been conducted on beta-1,3-xylanase from a marine bacterium, Alcaligenes sp. strain XY-234. The cloning and sequencing of the gene have been carried out and the results indicate that beta-1,3-xylanase is important for the beta-1,3-xylan hydrolysis.

Characterizes the carbohydrate-binding module (CBM) of beta-1,3-xylanase gene from marine bacterium. Role of CBM in beta-1,3-Xylan hydrolysis; Localization of beta-1,3-Xylan in red and green algae; Importance of beta-1,3-xylanase in the structural analysis of algae.

Crystals of β-1,3-xylanase (1,3-β- d-xylan xylanohydrolase; EC 3.2.1.32) from Thermotoga neapolitana strain DSM 4359 with maximum dimensions of 0.2 × 0.1 × 0.02 mm were grown using the sitting-drop vapour-diffusion method at 293 K over 24 h. The crystals diffracted to a resolution of 1.82 Å, allowing structure determination. The crystals belonged to space group P21, with unit-cell parameters a = 39.061, b = 75.828, c = 52.140 Å; each asymmetric unit cell contained a single molecule. [ABSTRACT FROM AUTHOR]

Here, we report the complete genome sequence of Flavobacterium sp. strain CFS9, a potential fish probiotic isolated from the body surface of Silurus asotus . The de novo assembly revealed a chromosome size of 5,370,016 bp with an estimated 4,374 open reading frames., Competing Interests: The authors declare no conflict of interest.

The cell walls of red and green algae contain β-1,3-xylan, which is hydrolysed by the endo-type enzyme β-1,3-xylanase. Notably, only marine-bacteria-derived β-1,3-xylanases have been functionally characterised to date. In this study, we characterised the enzymatic properties of a potential β-1,3-xylanase (BcXyn26B) derived from the human gut bacterium, Bacteroides cellulosilyticus WH2. The codon optimized BcXyn26B gene was synthesised and expressed in Escherichia coli BL21(DE3). The recombinant protein was purified by a two-step purification process using Ni-affinity chromatography followed by anion exchange chromatography, and its enzymatic properties were characterised. The recombinant BcXyn26B exhibited specific hydrolytic activity against β-1,3-xylan and released various β-1,3-xylooligosaccharides, with β-1,3-xylobiose as the primary product. The optimum reaction temperature was 50 °C, higher than that for other enzymes derived from marine bacteria. This study represents the first report on the identification, heterologous expression, and characterisation of β-1,3-xylanase from human gut microbes. Notably, the substrate specificity of BcXyn26B indicates that human gut Bacteroides species possess an unknown β-1,3-xylan utilisation system., Competing Interests: Declarations. Competing Interests: The authors declare that they have no affiliations with or involvement in any organisation or entity with any financial interest in the subject matter or materials discussed in this manuscript. Ethical approval: This article contains no studies with human participants or animals performed by any of the authors., (© 2024. The Author(s).)