Novosphingobium pentaromativorans sp. nov., a high-molecular-mass polycyclic aromatic hydrocarbon-degrading bacterium isolated from estuarine sediment.

A Gram-negative, yellow-pigmented, halophilic bacterial strain US6-1T, which degrades high-molecular-mass polycyclic aromatic hydrocarbons of two to five rings, was isolated from muddy sediment of Ulsan Bay, Republic of Korea. The 16S rRNA gene of the isolate showed high sequence similarity to Novosphingobium subarcticum (96.23 %) and Sphingopyxis alaskensis (96.18 %); however, the isolate formed a distinct phyletic line within the genus Novosphingobium. DNA-DNA relatedness between US6-1T and the closest strain N. subarcticum revealed that strain US6-1T was independent from this species. Isolate US6-1T had ubiquinone 10 and a DNA G + C ratio of 61.1 mol%. Major fatty acids were octadecanoic acid (18 : 1omega7), hexadecanoic acid (16 : 1omega7) and 2-hydroxy-myristic acid (14 : 0 2-OH). On the basis of polyphasic taxonomic evidence, strain US6-1T is proposed to represent a novel species in the genus Novosphingobium for which the name Novosphingobium pentaromativorans sp. nov. is proposed. The type strain is US6-1T (= KCTC 10454T = JCM 12182T).