Isolation and characterization of a novel piezotolerant bacterium Lysinibacillus yapensis sp. nov., from deep-sea sediment of the Yap Trench, Pacific Ocean.

A Gram-positive, aerobic, rod-shaped, spore-forming bacterium, designated YLB-03, with peritrichous flagella was isolated from deep-sea sediment of the Yap Trench at a depth of 4435 m. The bacterium was found to be catalase-positive but oxidase-negative. Growth of this bacterium was observed at 15-50°C (optimum 37°C), pH 5-10.5 (optimum 7), 0-5% NaCl (optimum 1%, w/v) and 0.1-50 MPa (optimum 0.1 MPa). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YLB-03 was a member of the genus Lysinibacillus. Strain YLB-03 was closely related to Lysinibacillus sinduriensis BLB-1 and Lysinibacillus chungkukjangi 2RL3-2 (98.4%), Lysinibacillus halotolerans LAM-612 (98.0%), Lysinibacillus telephonicus KT735049 (97.5%), Lysinibacillus endophyticus C9 (97.5%), Lysinibacillus composti NCCP-36 and Lysinibacillus massiliensis 4400831 (97.3%). The ANI and the GGDC DNA-DNA hybridization estimate values between strain YLB-03 and closely related type strains were 73.7-76.3% and 34.7-38.7%, respectively. The principal fatty acids were anteiso-C and iso-C. The G+C content of the chromosomal DNA was 39.6 mol%. The respiratory quinone was determined to be MK-7. The diagnostic amino acids in the cell wall peptidoglycan contained Lys-Asp (type A4α) and the cell-wall sugars were glucose and xylose. The polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified phospholipid. The combined genotypic and phenotypic data showed that strain YLB-03 represents a novel species within the genus Lysinibacillus, for which the name Lysinibacillus yapensis sp. nov. is proposed, with the type strain YLB-03 (= MCCC 1A12698 = JCM 32871).