Vibrio methylphosphonaticus sp. nov., a methylphosphonate-decomposing bacterium isolated from surface seawater in the...

A Gram-stain-negative, facultative anaerobic, methylphosphonate-decomposing, motile by a polar flagellum and rod-shaped marine bacterium, designated S4B1^T, was isolated from the surface seawater collected from the Yongle Atoll (Xisha Islands, PR China). The pairwise alignment showed the highest sequence similarity of 97.5 and 96.6 % to Vibrio aestuarianus subsp. cardii 12_122_3T3^T and Vibrio atypicus HHS02^T, respectively. Phylogenetic analysis based on 16S rRNA gene and the phylogenomic analysis of single-copy genes showed that strain S4B1^T belonged to the genus Vibrio and formed a close branch with Vibrio qingdaonensis ZSDZ65^T. Growth of strain S4B1^T occurred at 4-30 °C (optimum, 28 °C), at pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 2-7 % (w/v) NaCl (optimum, 3 %). The predominant fatty acids (>10 %) were C16 : 0, iso-C_16 : 0 and summed feature 3 (C_16 : 1  ω7c or/and C_16 : 1  ω6c). The DNA G+C content of the assembled genomic sequence was 44.3 mol%. Average nucleotide identity (ANI) values between S4B1^T and its reference species were lower than the threshold for species delineation (95-96 %), in which its highest ANI value with V. qingdaonensis ZSDZ65^T was 87.0 %. In silico DNA-DNA hybridization further showed that strain S4B1^T had less than 70 % similarity to its relatives. On the basis of the polyphasic evidence, strain S4B1^T is proposed to represent a novel species of the genus Vibrio, for which the name Vibrio methylphosphonaticus sp. nov. is proposed. The type strain is S4B1^T (=KCTC 92311^T=MCCC 1K06168^T).