Roseivivax jejudonensis sp. nov., isolated from the junction between the ocean and a freshwater spring at Jeju Island, South Korea.

Abstract

A Gram-stain negative, coccoid- or oval-shaped and non-gliding bacterial strain, designated CDM-17(T), was isolated from the zone where the ocean and a freshwater spring meet at Jeju island, South Korea, and subjected to a polyphasic taxonomic study. Strain CDM-17(T) was observed to form smooth, circular, glistening, slightly convex, light yellowish pink colonies on marine agar, and was found to grow optimally at pH 7.0-8.0, at 30°C and in the presence of 2-3% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain CDM-17(T) fell within the clade comprising the Roseivivax species, clustering with the type strain of Roseivivax sediminis with which it exhibited 98.3% sequence similarity value. Sequence similarities to the type strains of the other recognized Roseivivax species were 94.7-96.8%. Strain CDM-17(T) was found to contain Q-10 as the predominant ubiquinone and summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) as the major fatty acid. The major polar lipids were identified as phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid, an unidentified glycolipid and an unidentified lipid. The DNA G+C content of strain CDM-17(T) was determined to be 66.2mol% and its mean DNA-DNA relatedness value with Rsv. sediminis KCTC 23444(T) was 17.5±2.7%. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain CDM-17(T) is distinguishable from recognized Roseivivax species. On the basis of the data presented, strain CDM-17(T) is proposed to represent a novel species of the genus Roseivivax, for which the name Roseivivax jejudonensis sp. nov. is proposed. The type strain is CDM-17(T) (=KCTC 42110(T)=CECT 8625(T)).