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 degrees C and in the presence of 2% (w/v) NaCl. It contained Q-10 as the predominant ubiquinone and C-17:1 omega 6c and C-18:1 omega 7c 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.