A Gram-stain-negative, aerobic, motile and rod-shaped bacterial strain, designated OISW-25T, was isolated from seawater in Republic of Korea. Strain OISW-25T grew optimally at 25 °C and in the presence of 2.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain OISW-25T fell within the clade comprising the type strains of Colwellia species. Strain OISW-25T exhibited 16S rRNA gene sequence similarity values of 97.5, 97.2 and 97.1 % to the type strains of C. piezophila, C. maris and C. psychrerythraea, respectively, and of 93.6-96.6 % to the type strains of the other Colwellia species. The average nucleotide identity values between strain OISW-25T and C. piezophila ATCC BAA-637T and two non-type strains of C. psychrerythraea were 78.16-79.35 % and DNA-DNA relatedness value of strain OISW-25T with the type strain of C. maris was 17 %. The DNA G+C content of strain OISW-25T was 39.2 mol% (HPLC) or 38.7 mol% (genome data). Strain OISW-25T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0 as the major fatty acids. The major polar lipids of strain OISW-25T were phosphatidylethanolamine and phosphatidylglycerol. Distinguished phenotypic properties, along with the phylogenetic and genetic distinctiveness, revealed that strain OISW-25T is distinct from Colwellia species. On the basis of the data presented, strain OISW-25T is considered to represent a novel species of the genus Colwellia, for which the name Colwellia ponticola sp. nov. is proposed. The type strain is OISW-25T (=KCTC 62426T=NBRC 113187T).
Keywords: Colwellia ponticola; Novel species; polyphasic taxonomy; seawater.