Porphyrobacter dokdonensis sp. nov., isolated from sea water

A Gram-negative, non-motile, non-spore-forming, slightly halophilic bacterial strain, DSW-74^T, was isolated from sea water off the island of Dokdo, Korea, and its taxonomic position was investigated by a polyphasic study. Strain DSW-74^T grew optimally at 37°C and in the presence of 2 % (w/v) NaCl. It contained Q-10 as the predominant ubiquinone and C_17:1ω6c and C_18:1ω7c as the major fatty acids. Its DNA G+C content was 65.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DSW-74^T was most closely related to Porphyrobacter species. Similarity values between the 16S rRNA gene sequence of strain DSW-74^T and those of the type strains of recognized Porphyrobacter species and of Erythromicrobium ramosum were in the range 97.4-98.7 %. Strain DSW-74^T exhibited 16S rRNA gene sequence similarity values of < 97.5 % to recognized Erythrobacter species and the other species used in the phylogenetic analysis. DNA-DNA relatedness levels and differential phenotypic properties made it possible to categorize strain DSW-74^T as representing a novel Porphyrobacter species. On the basis of the taxonomic data presented, it is proposed that DSW-74^T (=KCTC 12395^T = DSM 17193^T) should be classified in the genus Porphyrobacter as the type strain of a novel species, Porphyrobacter dokdonensis sp. nov).