Sphingopyxis baekryungensis sp. nov., an orange-pigmented bacterium isolated from sea water of the Yellow Sea in Korea

A Gram-negative, motile, slightly halophilic bacterial strain, SW-150^T, was isolated from sea water of the Yellow Sea, Korea, and was characterized by a polyphasic taxonomic approach. Strain SW-150^T grew optimally at 25-30 °C and in the presence of 2 % (w/v) NaCl. The isolate could be distinguished from other Sphingopyxis species in producing an orange pigment. It contained ubiquinone-10 as the predominant respiratory lipoquinone and C_18:1ω7c and C_17:1ω6c as the major fatty acids. No 3-hydroxy fatty acids were detected. Major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 63 mol%. Comparative 16S rRNA gene sequence analyses showed that strain SW-150^T was phylogenetically affiliated to the genus Sphingopyxis of the family Sphingomonadaceae. Similarity values between the 16S rRNA gene sequences of strain SW-150^T and the type strains of Sphingopyxis species ranged from 91.6 to 94.2 %, making it possible to categorize strain SW-150^T as a species that is separate from previously described Sphingopyxis species. On the basis of phenotypic properties and phylogenetic distinctiveness, SW-150^T (=KCTC 12231^T=DSM 16222^T) should be classified as the type strain of a novel Sphingopyxis species, for which the name Sphingopyxis baekryungensis sp. nov. is proposed.