Sphingomonas dokdonensis sp. nov., isolated from soil

Abstract

A Gram-negative, rod-shaped, Sphingomonas-like bacterial strain, DS-4T, was isolated from soil of Dokdo, Korea, and its taxonomic position was investigated using a polyphasic approach. Strain DS-4T grew optimally on trypticase soy agar medium without NaCl at pH 6.0-6.5 and 25 °C. It contained Q-10 as the predominant ubiquinone and C18:1 ω7c, C16:0, C14:'0 2-OH and C16:1 ω7c and/or iso-C15:0 2-OH as the major fatty acids. Sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and unidentified phospholipid were the major polar lipids. The DNA G +C content was 66.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-4T fell within the evolutionary radiation comprising Sphingomonas species. Levels of 16S rRNA gene sequence similarity between strain DS-4T and the type strains of Sphingomonas species ranged from 93.0 to 97.6 %. DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain DS-4T differs from the recognized Sphingomonas species. On the basis of phenotypic, phylogenetic and genetic data, this strain represents a novel species of the genus Sphingomonas, for which the name Sphingomonas dokdonensis sp. nov. is proposed, with DS-4T (=KCTC 1254T=CIP 108841T) as the type strain.