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 C18 : 1ω7c and C16 : 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 class Alphaproteobacteria, 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)).