Lolliginicoccus levis gen. nov., sp. nov., a novel bacterium isolated from the brain of the Chiroteuthis picteti squid, and reclassification of two Hoyosella species as Lolliginicoccus suaedae comb. nov. and Lolliginicoccus lacisalsi comb. nov.

Abstract

A Gram-stain-positive, non-motile, mesophilic, aerobic, coccus-shaped bacterium, designated strain Y7R2T, was isolated from the brain of a Chiroteuthis picteti 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 Hoyosella (96.1 % similarity to the type strain of the type species Hoyosella altamirensis ) and formed a separate distinct cluster in a stable, deep-branching lineage with the type strains of Hoyosella suaedae and Hoyosella lacisalsi (98.7–99.5% similarities). The major fatty acids (>10 %) of strain Y7R2T were C17 : 1 ω8c, C15 : 0, C16 : 1 ω6c/C16 : 1 ω7c and C16 : 0, 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 ( H. suaedae and H. lacisalsi ) but different from those of core Hoyosella species (including H. altamirensis ). These results suggested that Y7R2T, H. suaedae and H. lacisalsi strains should be assigned to a novel genus. Furthermore, strain Y7R2T 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 H. suaedae and H. lacisalsi . These data indicated that strain Y7R2T should be assigned to a novel genus and species, for which the name Lolliginicoccus levis gen. nov., sp. nov. is proposed. The type strain is Y7R2T (=NBRC 114883T=KCTC 49749T). Accordingly, reclassification of H. suaedae and H. lacisalsi as Lolliginicoccus suaedae comb. nov. (type species) and Lolliginicoccus lacisalsi comb. nov. is also proposed.