Roseovarius ponticola sp. nov., a novel lipolytic bacterium of the family Rhodobacteraceae isolated from seawater.

Abstract

A lipolytic, Gram-negative, aerobic, non-motile and pleomorphic bacterial strain, designated W-SW3T, was isolated from seawater around Wando, an island of South Korea, and its taxonomic position was determined using a polyphasic approach. Its optimal growth occurred at 30°C, pH 7.0-8.0 and 2.0-4.0% (w/v) NaCl. Neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain W-SW3T belonged to the genus Roseovarius of the family Rhodobacteraceae, by showing the highest 16S rRNA gene sequence similarity value (97.3%) to the type strain of Roseovarius nanhaiticus. Strain W-SW3T exhibited 16S rRNA gene sequence similarities of 93.2-95.6% to the type strains of the other Roseovarius species. Ubiquinone-10 was found as the predominant ubiquinone and C18:1ω7c and C16:0 were found as the major fatty acids. Phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified lipid and one unidentified aminolipid were major polar lipids detected. The DNA G + C content of strain W-SW3T was 63.9mol%. Mean DNA-DNA relatedness values of strain W-SW3T with the type strains of R. nanhaiticus and R. antarcticus were 18 and 9%, respectively. The phenotypic properties, together with the phylogenetic and genetic data, made it possible strain W-SW3T to be separated from other recognized species of the genus Roseovarius. On the basis of the data presented, strain W-SW3T represents a novel species of the genus Roseovarius, for which the name Roseovarius ponticola sp. nov. is proposed. The type strain is W-SW3T (= KCTC 62424T = KACC 19615T = NBRC 113186T).