Description of Domibacillus iocasae sp. nov., isolated from deep-sea sediment, and emended description of the genus Domibacillus

In this study, we report a novel Gram-stain-positive bacterium, designated strain S6 T , isolated from deep-sea sediment in Okinawa Trough. Growth of strain S6 T occurred at 10-45 °C (optimum, 35 °C), at pH 6.0-11.0 (optimum, 8.0) and with 0-8 % (w/v) NaCl (optimum, 3 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain S6 T belonged to the genus Domibacillus . The closest phylogenetic neighbours of strain S6 T were Domibacillus robiginosus WS 4628 T ( = DSM 25058 T ) (98.6 %16S rRNA gene sequence similarity), D. indicus SD111 T ( = DSM 28032 T ) (97.6 %), D. enclensis NIO-1016 T ( = DSM 25145 T ) (97.6 %), and ' D. tundrae ' PAMC 80007 ( = DSM 29572) (97.6 %). Levels of similarity between strain S6 T and other close relatives were below 96 %. The levels of DNA-DNA relatedness between strain S6 T and its closest relatives in the genus Domibacillus were well below 70 %. The genomic DNA G+C content of strain S6 T was 44.4 mol%. The major menaquinone was MK-6. The polar lipids of strain S6 T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylethanolamine and three unknown phospholipids. Strain S6 T harboured meso -diaminopimelic acid as the diagnostic diamino acid and an A1γ type of peptidoglycan. The major cell-wall sugars of strain S6 T were xylose and glucose. Phylogenetic, physiological, biochemical and morphological analyses suggest that this strain represents a novel species of the genus Domibacillus , for which the name Domibacillus iocasae sp. nov. is proposed. The type strain is S6 T ( = DSM 29979 T  = CCTCC AB 2015183 T ). An emended description of the genus Domibacillus is also provided.