Meridianimarinicoccus roseus gen. nov., sp. nov., a novel genus of the family Rhodobacteraceae isolated from seawater.

A Gram-stain negative, pink-pigmented, strictly aerobic, non-motile and coccoid-shaped bacterial strain, designated TG-679T, was isolated from a deep-sea water sample collected from the South China Sea. Cells of strain TG-679T were catalase- and oxidase-positive, lacked bacteriochlorophyll a and carotenoid. Strain TG-679T was found to grow at 10-40 °C (optimum, 28 °C), pH 5.5-10.0 (optimum, pH 7.5) and with 0.5-2.0 % (w/v) NaCl (optimum, 1.5 %). Chemotaxonomic analysis of strain TG-679T indicated that the sole respiratory quinone was Q-10, the predominant cellular fatty acid was C18 : 1ω7c, and the major polar lipids consisted of phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified phospholipid and two unidentified glycolipids. The genomic DNA G+C content of strain TG-679T was 65.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain TG-679T constituted a separated branch in the family Rhodobacteraceae. Differential phenotypic properties, together with phylogenetic distinctiveness, demonstrated that strain TG-679T is clearly distinct from any validly published genus. Based on polyphasic taxonomic characterization, strain TG-679T is considered to represent a novel species of a novel genus, for which the name Meridianimarinicoccus roseus gen. nov., sp. nov. is proposed. The type strain of the species is TG-679T (=KCTC 62454T=MCCC 1K03496T).