Aquimixticola soesokkakensis gen. nov., sp. nov., a novel lipolytic alphaproteobacterium isolated from the junction between the ocean and a freshwater spring, and reclassification of Roseovarius marinus as Pacificibacter marinus comb. nov. and emended description of the genus Pacificibacter

A Gram-negative, aerobic, non-flagellated and rod-shaped or ovoid bacterial strain, designated DSSK2-3^T, was isolated from the junction between the ocean and a freshwater spring at Jeju island, South Korea. Strain DSSK2-3^T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0–3.0 % (w/v) NaCl. Neighbour-joining and maximum-likelihood phylogenetic trees based on 16S rRNA gene sequences revealed that strain DSSK2-3^T joins the cluster comprising the type strains of Pacificibacter maritimus and Roseovarius marinus, with which it exhibited the highest sequence similarity values of 96.04 and 95.75 %, respectively. Sequence similarities to the type strains of other recognized species were <95.74 %. Strain DSSK2-3^T was found to contain Q-10 as the predominant ubiquinone and C_18:1ω7c as the major fatty acid. The polar lipid profile of strain DSSK2-3^T was found to contain phosphatidylglycerol, an unidentified lipid and an unidentified aminolipid as major components, which distinguished the strain from those of phylogenetically related taxa. The DNA G+C content of strain DSSK2-3^T was determined to be 60.8 mol%. On the basis of the phylogenetic data and the chemotaxonomic and other phenotypic properties, strain DSSK2-3^T is considered to represent a new genus and species within the class Alphaproteobacteria, for which the name Aquimixticola soesokkakensis gen. nov., sp. nov. is proposed. The type strain of A. soesokkakensis is DSSK2-3^T (=KCTC 42137^T = CECT 8620^T). In this study, it is also proposed that R. marinus should be reclassified as a member of the genus Pacificibacter and the description of the genus Pacificibacter is emended.