Polaribacter undariae sp. nov., isolated from a brown alga reservoir

Abstract

A Gram-stain-negative, non-flagellated, non-gliding, aerobic and rod-shaped or ovoid bacterial strain, designated W-BA7(T), was isolated from a brown alga reservoir on the South Sea in South Korea. This strain grew optimally at 25 °C, at pH 7.0-8.0 and in the presence of approximately 2.0% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain W-BA7(T) belonged to the genus Polaribacter, clustering coherently with the type strain of Polaribacter sejongensis, showing 99.3% sequence similarity. Strain W-BA7(T) exhibited 16S rRNA gene sequence similarity of 93.4-98.6% to the type strains of the other species of the genus Polaribacter. Strain W-BA7(T) contained MK-6 as the predominant menaquinone and iso-C15 : 0 3-OH and anteiso-C15 : 0 as the major fatty acids. The major polar lipids of strain W-BA7(T) were phosphatidylethanolamine, three unidentified lipids, one unidentified glycolipid, one unidentified aminolipid and one unidentified aminophospholipid. The DNA G+C content of strain W-BA7(T) was 31.9 mol%, and the mean DNA-DNA relatedness with the type strains of four phylogenetically related species of the genus Polaribacter was 12-27%. Differential phenotypic properties, together with its phylogenetic and genetic distinctiveness, revealed that strain W-BA7(T) is separated from recognized species of the genus Polaribacter. On the basis of the data presented, strain W-BA7(T) is considered to represent a novel species of the genus Polaribacter, for which the name Polaribacter undariae sp. nov. is proposed. The type strain is W-BA7(T) ( =KCTC 42175(T) =CECT 8670(T)).