Draconibacterium orientale gen. nov., sp. nov., isolated from two distinct marine environments, and proposal of Draconibacteriaceae fam. nov.

Abstract

The taxonomic characteristics of two bacterial strains, FH5T and SS4, isolated from enrichment cultures obtained from two distinct marine environments, were determined. These bacteria were Gram-stain-negative, facultatively anaerobic rods. Growth occurred at 20–40 °C (optimum, 28–32 °C), pH 5.5–9.0 (optimum, pH 7.0–7.5) and in the presence of 1–7 % NaCl (optimum, 2–4 %). The major cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Menaquinone 7 (MK-7) was the sole respiratory quinone. The major polar lipids were phosphatidylethanolamine, an unkown phospholipid and an unknown lipid. The DNA G+C contents of strains FH5T and SS4 were both determined to be 42.0 mol%. The results of DNA–DNA hybridization studies indicated that the FH5T and SS4 genomes share greater than 95 % relatedness. The strains formed a distinct phyletic line within the class Bacteroidia , with less than 89.4 % sequence similarity to their closest relatives with validly published names. On the basis of physiological and biochemical characteristics, 16S rRNA gene sequences and chemical properties, a novel genus and species, Draconibacterium orientale gen. nov., sp. nov., within the class Bacteroidia , are proposed, with strain FH5T ( = DSM 25947T = CICC 10585T) as the type strain. In addition, a new family, Draconibacteriaceae fam. nov., is proposed to accommodate Draconibacterium gen. nov.