Comparative analysis of 16S rRNA signature sequences of the genus Idiomarina and Idiomarina woesei sp. nov., a novel marine bacterium isolated from the Andaman Sea

Abstract

A Gram-negative, short rod, aerobic bacterium, designated W11(T), was isolated from seawater. Heterotrophic growth was observed at 10-45 °C and pH 6-10. Optimal growth was observed at 30-37 °C and pH 7-9. It can grow in the presence of 0.5-12% NaCl (w/v), and the optimal NaCl required for growth was 5-6%. 16S rRNA gene sequence similarity revealed that strain W11(T) clustered within the radiation of the genus Idiomarina and showed 99.24% similarity with Idiomarina donghaiensis JCM 15533(T), 97.64% with Idiomarina marina JCM 15083(T), 97.37% with Idiomarina tainanensis JCM 15084(T) and 97.16% with Idiomarina maritima JCM 15534(T). DNA-DNA similarities between strains W11(T) with other closely related strains were below 70%. Polar lipids included a phosphatidylgylycerol, a diphosphatidylglycerol, a phosphatidylethanolamine, an unidentified phosopholipid, two unidentified aminolipids and two unidentified lipids. DNA G + C content was 41.2 ± 0.1 mol%. Major fatty acids were iso-C15:0, iso-C17:0, iso-C17:1ω9c, C16:0, iso-C11:0 3OH and C16:1ω7c/C16:1ω7c. The isoprenoid ubiquinone was Q8. On the basis of the present polyphasic taxonomic study, strain W11(T) is considered to represent a novel species of the genus Idiomarina, for which the name Idiomarina woesei sp. nov. is proposed. The type strain is W11(T) (= DSM 27808(T) = JCM 19499(T) = LMG 27903(T)).

Keywords: DNA–DNA hybridization; Fatty acid; Idiomarina woesei sp. nov.; Polar lipid; Quinone.