A Gram-positive, rod-shaped, endospore-forming bacterium with multiple flagella, designated XXST-01T, was isolated from deep-sea sediment of Yap Trench with a depth of 6300 m. Activity of oxidase and catalase were found to be positive. Growth was observed at 10-45 °C (optimum 37 °C), pH 6-9 (optimum 7.0), 0-6% NaCl (optimum 0-0.5%, w/v) and 0.1-50 MPa (optimum 0.1 MPa). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XXST-01T belonged to the genus Bacillus. Strain XXST-01T was closely related to Bacillus kyonggiensis NB22T (98.4%), Bacillus siralis 171544T (97.53%), Bacillus massiliosenegalensis JC6T (97.30%), Bacillus oceanisediminis H2T (97.27%), Bacillus mesophilum IITR-54T (97.12%) and Bacillus depressus BZ1T (97.09%). The ANI and the DNA-DNA hybridization estimate values between strain XXST-01T and closely related type strains were 70.91-90.15% and 19.80-40.50%, respectively. The principal fatty acids were iso-C15:0, anteiso-C15:0, iso-C16:0, and iso-C14:0. The G+C content of the chromosomal DNA was 38.2 mol%. The respiratory quinone was determined to be MK-7. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid and four unidentified aminophospholipids. The combined genotypic and phenotypic data show that strain XXST-01T represents a novel species within the genus Bacillus, for which the name Bacillus yapensis sp. nov. is proposed, with the type strain XXST-01T (=MCCC 1A14143T = JCM 33181T).
Keywords: Bacillus yapensis sp. nov.; Deep-sea sediment; Yap Trench.