Marinobacter excellens sp. nov., isolated from sediments of the Sea of Japan

Abstract

Five strains of halophilic, Gram-negative marine bacteria (KMM 3809T, KMM 3814, KMM 3815, KMM 3817 and KMM 3818) were isolated from sediments collected from Chazhma Bay, Sea of Japan. Phylogenetic 16S rRNA gene sequence-based analysis placed these bacteria in a clade within the genus Marinobacter in the γ-Proteobacteria. KMM 3809T showed highest 16S rRNA gene sequence similarity of 97·3 % to Marinobacter litoralis and 96·9 % to Marinobacter hydrocarbonoclasticus and Marinobacter aquaeolei. DNA–DNA hybridization between the five isolates was at the conspecific level (94–96 %) and that among the closest phylogenetic neighbours ranged from 45·0 to 62·5 %. The new organisms were susceptible to polymyxin. Predominant fatty acids were C16 : 0, C16 : 1 ω9c, C16 : 1 ω7c and C18 : 1 ω9c. Phylogenetic evidence, along with phenotypic and genotypic characteristics, showed that the bacteria constituted a novel species of the genus Marinobacter. The name Marinobacter excellens sp. nov. is proposed for this species, with the type strain KMM 3809T (=CIP 107686T).