Porphyrobacter donghaensis sp nov., isolated from sea water of the East Sea in Korea

Two Gram-negative, motile, non-spore-forming, bacteriochlorophyll a-containing slightly halophilic strains, SW-132(T) and SW-158, were isolated from sea water of the East Sea in Korea, and subjected to a polyphasic taxonomic study. The two isolates were characterized chemotaxonomically as having Q-10 as the predominant respiratory lipoquinone and major amounts of unsaturated fatty acids C(18:1)omega7c and C(17:1)omega6c. The DNA G + C contents of the two strains were in the range 66.8-65.9 mol%. The 16S rRNA gene sequences of strains SW-132(T) and SW-158 were 99-9% (1 nt difference) similar and their mean level of DNA-DNA relatedness was 86%. The 16S rRNA gene sequence analysis showed that strains SW-132(T) and SW-158 are phylogenetically closely related to Porphyrobacter species and Erythromicrobium ramosum. Similarities between the 16S rRNA gene sequences of strains SW-132(T) and SW-158 and the type strains of Porphyrobacter species and E. ramosum ranged from 97-8 to 99-0%, DNA-DNA relatedness data indicated that strains SW-132(T) and SW-158 are members of a genomic species that is separate from the four Porphyrobacter species. On the basis of phenotypic and phylogenetic data and genetic distinctiveness, strains SW-132(T) ( = KCTC 12229(T) = DSM 16220(T)) and SW-158 ( = KCTC 12230) are classified as a novel Porphyrobacter species, for which the name Porphyrobacter donghaensis sp. nov. is proposed.