| Abstract |
Two novel strains, designated YLB-02T and YLB-04T, were isolated from the deep-sea sediments of Yap Trench located in the Pacific Ocean. Cells of the strains were Gram-stain-positive, oxidase- and catalase-positive and rod-shaped. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YLB-02T belonged to the genus Oceanobacillus and strain YLB-04T belonged to the genus Bacillus. Strain YLB-02T showed similarities of 96.9 % with Ornithinibacillus contaminans CCUG 53201T, 96.3 % with Oceanobacillus profundus CL-MP28T, 96.1 % with Oceanobacillus halophilus J8BT and 95.7 % with Oceanobacillus bengalensis Ma-21T. Strain YLB-04T showed the highest sequence similarity of 97.4 % with Bacillus notoginsengisoli SYP-B691T. The average nucleotide identity (ANI) and the DNA-DNA hybridisation (DDH) estimate values for strain YLB-02T and YLB-04T with their related type strains were below the respective threshold for species differentiation. The G+C contents of strains YLB-02T and YLB-04T were 37.3 and 45.4 mol%. The predominant (>10 %) cellular fatty acids of strain YLB-02T were iso-C14 : 0, iso-C15 : 0, iso-C16 : 0 and C16 : 1ω7c alcohol, and those of strain YLB-04T were C16 : 0, iso-C15 : 0, anteiso-C15 : 0 and C18 : 0. Their predominant ubiquinone was MK-7. The cell-wall peptidoglycan of strain YLB-02T contained glutamic acid, alanine, aspartic acid, lysine and ornithine, but no meso-diaminopimelic acid, while strain YLB-04T contained meso-diaminopimelic acid, glutamic acid, alanine, aspartic acid, lysine and ornithine. In addition to diphosphatidylglycerol (DPG) and phosphatidylglycerol (PG), the polar lipids of strain YLB-02T also consisted of an unidentified glycolipid (GL), two unidentified polar lipids (L1 and L2) and two unidentified phospholipids (PL1 and PL2), and those of strain YLB-04T also consisted of phosphatidylethanolamine (PE) and an unidentified phospholipid (PL). Based on phenotypic, genotypic and chemotaxonomic characteristics, two novel species are proposed, Oceanobacillus piezotolerans sp. nov. with YLB-02T (=MCCC 1A12699T=JCM 32870T) and Bacillus piezotolerans sp. nov. with YLB-04T (=MCCC 1A12711T=JCM 32872T) as the type strains.
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