gen. nov., sp. nov., a novel bacterium isolated from the brain of the squid, and reclassification of two species as comb. nov. and comb. nov.

A Gram-stain-positive, non-motile, mesophilic, aerobic, coccus-shaped bacterium, designated strain Y7R2, was isolated from the brain of a squid living in mesopelagic water near Muroto, Kochi, Japan. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain was most closely related to the genus (96.1 % similarity to the type strain of the type species ) and formed a separate distinct cluster in a stable, deep-branching lineage with the type strains of and (98.7-99.5% similarities). The major fatty acids (>10 %) of strain Y7R2 were C ω8, C, C ω6/C ω7 and C, and the isoprenoid quinones were menaquinone-7 (57.8 %) and menaquinone-8 (42.2 %). The principal polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol, and the DNA G+C content was 68.0 %. These chemotaxonomic features, with the exception of the fatty acid composition, were similar to those of the phylogenetically clustered species ( and ) but different from those of core species (including ). These results suggested that Y7R2, and strains should be assigned to a novel genus. Furthermore, strain Y7R2 showed low average nucleotide identity values (88.0-88.2 %) and low digital DNA-DNA hybridization values (34.3-34.7 %) to the type strains of and . These data indicated that strain Y7R2 should be assigned to a novel genus and species, for which the name gen. nov., sp. nov. is proposed. The type strain is Y7R2 (=NBRC 114883=KCTC 49749). Accordingly, reclassification of and as comb. nov. (type species) and comb. nov. is also proposed.