Oceanimonas pelagia sp. nov., a novel biosurfactant-producing and plastic-degrading potential bacterium isolated from marine coastal sediment.

A marine bacterial strain, named NTOU-MSR1, was isolated from marine sediment of northern coast of Taiwan. This bacterium was Gram-stain-negative, aerobic, and motile, with a single flagellum. Its rod-shaped cells measured approximately 0.5-0.6 µm in width and 1.8-2.0 μm in length. NTOU-MSR1 grew at temperatures ranging from 10 to 45 °C, optimally at 30 °C. The pH range for growth was 7.0-10.0, with optimal growth at pH 7.0-8.0. It tolerated NaCl concentrations up to 12%. The cell membrane predominantly contained fatty acids such Cω7c, Cω7c, and C. The overall genome relatedness indices indicated that strain NTOU-MSR1 had an average nucleotide identity (ANI) of 87.88% and a digital DNA-DNA hybridization (dDDH) value of 35.40% compared to its closest related species, O. marisflavi 102-Na3. These values fell below the 95% and 70% threshold for species delineation, respectively. These findings suggested that the strain NTOU-MSR1 was a new member of the Oceanimonas genus. Its genomic DNA had a G + C content of 61.0 mol%. Genomic analysis revealed genes associated with the catechol branch of β- ketoadipate pathway for degrading polycyclic aromatic hydrocarbons, resistance to heavy metal, biosynthesis of polyhydroxybutyrate and the production of glycoside hydrolases (GH19, GH23, and GH103) for chitin and glycan digestion. Additionally, NTOU-MSR1 was capable of synthesizing biosurfactants and potentially degrading plastic. The proposed name for this new species is Oceanimonas pelagia, with the type strain designated as NTOU-MSR1 (= BCRC 81403 = JCM 36023).