Polaribacter marinivivus sp. nov., a member of the family Flavobacteriaceae isolated from seawater

A Gram-stain negative, non-flagellated, non-gliding, aerobic and rod-shaped bacterium, designated GYSW-15^T, was isolated from a seawater of Geoje island on the South Sea, South Korea, and subjected to a polyphasic taxonomic approach. Strain GYSW-15^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of approximately 2.0 % (w/v) NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain GYSW-15^T belongs to the genus Polaribacter, clustering coherently with the type strain of Polaribacter porphyrae showing sequence similarity value of 97.0 %. Strain GYSW-15^T exhibited 16S rRNA gene sequence similarity values of 94.3–96.4 % to the type strains of the other Polaribacter species. Strain GYSW-15^T was found to contain MK-6 as the predominant menaquinone and iso-C_15:0, iso-C_15:1 G, iso-C_16:0 3-OH and summed feature 3 (C_16:1 ω7c and/or C_16:1 ω6c) as the major fatty acids. The polar lipid profile of strain GYSW-15^T containing phosphatidylethanolamine and an unidentified lipid as major components was similar to that of the type strain of P. porphyrae. The DNA G + C content of strain GYSW-15^T was determined to be 31.2 mol% and its mean DNA–DNA relatedness with P. porphyrae LMG 26671^T was 17 %. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain GYSW-15^T is separated from recognized Polaribacter species. On the basis of the data presented, strain GYSW-15^T is considered to represent a novel species of the genus Polaribacter, for which the name Polaribacter marinivivus sp. nov. is proposed. The type strain is GYSW-15^T ( = KCTC 42156^T = CECT 8655^T)