Ascidiaceihabitans donghaensis gen. nov., sp. nov., isolated from the golden sea squirt Halocynthia aurantium

A Gram-stain-negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, designated RSS1-M3^T, was isolated from a golden sea squirt (Halocynthia aurantium) collected from the East Sea, South Korea. Strain RSS1-M3^T grew optimally at 30 °C, at pH 7.0–8.0 and in presence of 2.0 % (w/v) NaCl. Strain RSS1-M3^T exhibited the highest 16S rRNA gene sequence similarity (96.55 %) to the type strain of Pelagicola litoralis. Neighbour-joining and maximum-likelihood phylogenetic trees based on 16S rRNA gene sequences revealed that strain RSS1-M3^T clustered with the type strains, or proposed type strains, of Planktotalea frisia, Pacificibacter maritimus, Roseovarius marinus and Halocynthiibacter namhaensis, showing sequence similarity of 94.88–96.32 %. Strain RSS1-M3^T contained Q-10 as the predominant ubiquinone and C_{18: 1}ω7c and C_{16: 0} as the major fatty acids. The polar lipid profile of strain RSS1-M3^T, containing phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified aminolipid and one unidentified lipid as major components, could be distinguished from those of the phylogenetically related genera. The DNA G+C content of strain RSS1-M3^T was 55.8 mol%. On the basis of the phylogenetic, chemotaxonomic and phenotypic properties, strain RSS1-M3^T is considered to represent a novel species of a new genus within the classAlphaproteobacteria, for which the name Ascidiaceihabitans donghaensis gen. nov., sp. nov. is proposed. The type strain is RSS1-M3^T (= KCTC 42118^T = CECT 8599^T).