Description of Bacillus kexueae sp. nov. and Bacillus manusensis sp. nov., isolated from hydrothermal sediments.

Two Gram-staining-positive, strictly aerobic bacilli, designated as strains Ma50-5 and Ma50-6, were isolated from the hydrothermal sediments of Manus Basin in the western Pacific Ocean. Based on 16S rRNA gene sequence, strains Ma50-5 and Ma50-6 were most closely related to Bacillus alveayuensis (97.0 and 97.2 % identity, respectively). The 16S rRNA gene sequence identity between strains Ma50-5 and Ma50-6 was 97.4 %. The identities between strains Ma50-5 and Ma50-6 and other closely related organisms were below 97.0 %. The G+C contents of the genomic DNA of strains Ma50-5 and Ma50-6 were 43.4 and 47.6 mol%, respectively. The major fatty acids (>10 %) of both strains were iso-C15 : 0 and iso-C17 : 0. The predominant isoprenoid quinone detected in both strains was menaquinone-7. Phylogenetic, physiological, biochemical and morphological analyses suggested that strains Ma50-5 and Ma50-6 represent two novel species of the genus Bacillus, for which the names Bacillus kexueae sp. nov. (type strain Ma50-5=KCTC 33881=CCTCC AB 2017020) and Bacillus manusensis sp. nov. (type strain Ma50-6=KCTC 33882=CCTCC AB 2017019), respectively, are proposed.