Sphingomonas polyaromaticivorans sp nov., a polycyclic aromatic hydrocarbon-degrading bacterium from an oil port water sample

Abstract

A bacterial strain (B2-7(T)) capable of degrading a wide range of polycyclic aromatic hydrocarbon compounds (2-4 rings) was isolated from a water sample taken from Botan Oil Port in Xiamen, China. The isolate was Gram-negative, short-rod-shaped, aerobic, non-motile and formed yellow-pigmented colonies on LB medium. Cells of strain B2-7(T) were catalase-positive and oxidase-negative. Optimal growth of strain B2-7(T) was observed at pH 7.0, at 26 degrees C and in 0.5% NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain B2-7(T) grouped with members of the genus Sphingomonas and it showed 16S rRNA gene sequence similarity of 95.40% to Sphingomonas yunnanensis YIM 003(T). The major polar lipids were phosphatidylethanolamine, phosphatidylcholine and sphingoglycolipid. Q-10 and sym-homospermidine were the predominant ubiquinone and polyamine components, respectively. The major fatty acids were C-18:1 omega 7c (67.2%), C-14:0 2-OH (10.0%) and C-16:0 (9.6%). The G + C content of the genomic DNA was 61.8 mol%. Based on phenotypic properties, and phylogenetic and genomic data, strain B2-7(T) represents a novel species of the genus Sphingomonas within the class Alphaproteobacteria, for which the name Sphingomonas polyaromaticivorans sp. nov. is proposed. The type strain is B2-7(T) (=KCCM 42951(T)=JCM 16711(T)).