Thalassotalea ponticola sp. nov., isolated from seawater, reclassification of Thalassomonas fusca as Thalassotalea fusca comb. nov. and emended description of the genus Thalassotalea

Abstract

A Gram-stain-negative, aerobic, non-flagellated and rod-shaped or ovoid bacterial strain, designated GJSW-36T, was isolated from seawater at Geoje island in the South Sea, South Korea. Strain GJSW-36T grew optimally at pH 7.0–8.0, at 25 °C and in the presence of 2 % (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain GJSW-36T fell within the clade comprising the type strains of species of the genus Thalassotalea and Thalassomonas fusca . Strain GJSW-36T exhibited 16S rRNA gene sequence similarity values of 94.2–96.0 % to the type strains of species of the genus Thalassotalea and Thalassomonas fusca and of 93.8–94.5 % to the type strains of the other species of the genus Thalassomonas . Strain GJSW-36T contained ubiquinone-8 (Q-8) as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C17 : 1ω8c and C16 : 0 as the major fatty acids. The major polar lipids of strain GJSW-36T were phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content of strain GJSW-36T was 45.1 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain GJSW-36T is separated from species of the genus Thalassotalea and Thalassomonas fusca . On the basis of the data presented, strain GJSW-36T is considered to represent a novel species of the genus Thalassotalea , for which the name Thalassotalea ponticola sp. nov. is proposed. The type strain is GJSW-36T ( = KCTC 42155T = CECT 8656T). From this study, it is also proposed that Thalassomonas fusca should be reclassified as a member of the genus Thalassotalea and the description of the genus Thalassotalea is emended.