Thalassobius maritimus sp. nov., isolated from seawater

Abstract

A Gram-stain-negative, aerobic, motile, rod-shaped bacterial strain, GSW-M6T, was isolated from seawater of Geoje island, Korea, and was subjected to a polyphasic taxonomic study. Strain GSW-M6T grew optimally at pH 7.0–8.0, at 30 °C and in the presence of 2 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GSW-M6T clustered with Thalassobius aestuarii, Thalassobius gelatinovorus and Thalassobius mediterraneus. Strain GSW-M6T exhibited 96.2–96.9 % 16S rRNA gene sequence similarity to the type strains of these three Thalassobius species. Strain GSW-M6T contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The polar lipid profiles of strain GSW-M6T and the type strains of the three Thalassobius species were similar, with phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unidentified lipid as common major components. The DNA G+C content of strain GSW-M6T was 57 mol%. The mean level of DNA–DNA relatedness between strain GSW-M6T and the type strain of Thalassobius gelatinovorus was 17 %. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, enabled strain GSW-M6T to be differentiated from recognized species of the genus Thalassobius. On the basis of the data presented, strain GSW-M6T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius maritimus sp. nov. is proposed. The type strain is GSW-M6T ( = KCTC 23347T  = CCUG 60021T).