Rheinheimera aquimaris sp. nov., isolated from seawater of the East Sea in Korea

Abstract

Two Gram-negative, motile, non-spore-forming bacterial strains, SW-353T and SW-369, were isolated from seawater from the East Sea, Korea, and their taxonomic positions were investigated by means of a polyphasic study. Strains SW-353T and SW-369 grew optimally at 30-37 °C and pH 7.0-8.0. Strains SW-353T and SW-369 contained Q-8 as the predominant ubiquinone and contained C16:0, C18:1ω7c and C16:1ω7c and/or iso-C15:0 2-OH as the major fatty acids. The DNA G + C contents were 50.1 and 50.5 mol%. Strains SW-353T and SW-369 exhibited no differences in their 16S rRNA gene sequences and showed a mean DNA-DNA relatedness level of 91 %. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains SW-353T and SW-369 belong to the genus Rheinheimera. Similarity values between the 16S rRNA gene sequences of the two isolates and the type strains of the recognized Rheinheimera species were in the range 96.6-97.9 %. DNA-DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness, demonstrated that strains SW-353T and SW-369 differ from the recognized Rheinheimera species. On the basis of phenotypic, phylogenetic and genetic data, therefore, strains SW-353T and SW-369 represent a novel species of the genus Rheinheimera, for which the name Rheinheimera aquimaris sp. nov. is proposed. The type strain is SW-353T (=KCTC 12840T=JCM 14331T).