Polaribacter insulae sp. nov., isolated from a tidal flat.

A Gram-stain-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, designated OITF-22, was isolated from a tidal flat of Oido, an island of South Korea, and subjected to a polyphasic taxonomic study. Strain OITF-22 grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. The phylogenetic trees based on 16S rRNA gene sequences showed that strain OITF-22 fell within the clade comprising the type strains of Polaribacter species. Strain OITF-22 exhibited 16S rRNA gene sequence similarity values of 97.2-99.4 % to the type strains of Polaribacter vadi, P. haliotis, P. atrinae, P. dokdonensis, P. litorisediminis,P. reichenbachii, P. irgensii and P. marinaquae, and of 93.0-96.9 % to the type strains of the other Polaribacter species. Strain OITF-22 contained MK-6 as the predominant menaquinone and iso-C15 : 0 and iso-C15 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain OITF-22 were phosphatidylethanolamine and one unidentified lipid. The DNA G+C content of strain OITF-22 was 32.3 mol% and its DNA-DNA relatedness values with the type strains of the eight phylogenetically most closely related Polaribacter species were 9-32 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain OITF-22 is separated from recognized species of the genus Polaribacter. On the basis of the data presented, strain OITF-22 is considered to represent a novel species of the genus Polaribacter, for which the name Polaribacter insulae sp. nov. is proposed. The type strain is OITF-22 (=KCTC 52658=NBRC 112706).