Ornithinibacillus xuwenensis sp. nov., A Novel Thermotolerant Bacterium Isolated from Mangrove Sediment.

A Gram-stain positive, long-rod-shaped, motile, and aerobic bacterial strain, designated 16A2E, was isolated from mangrove sediment sample. The 16S rRNA gene sequence similarity analysis indicated that strain 16A2E exhibited high similarity to Ornithinibacillus contaminans CCUG 53201 (98.2%), Ornithinibacillus bavariensis WSBC 24001 (98.1%), and Ornithinibacillus scapharcae TW25 (97.7%). Strain 16A2E grew within a temperature range of 20-50 °C (optimum 40 °C), a pH range of 6.0-9.0 (optimum pH 8.0), and in the presence of 0-10% (w/v) NaCl (optimum 1%). The genome size of strain 16A2E is 3.60 Mbp, with a G + C content of 36.7%. The overall genome related index (OGRI) analyses revealed low average nucleotide identity (ANI < 75.9%), average amino acid identity (AAI < 77.5%), and digital DNA-DNA hybridization (dDDH < 19.8%) with other species in the genus Ornithinibacillus. Chemotaxonomic analyses revealed that the major polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phospholipids, and an aminophospholipid. The predominant fatty acids were iso-C, anteiso-C, and anteiso-C. The sole respiratory quinone was menaquinone-7 (MK-7), and the peptidoglycan amino acid type was determined to be A4β. Based on phenotypic and genotypic analyses, strain 16A2E (= GDMCC 1.4379 = JCM 36753) represents a novel species within the genus Ornithinibacillus, for which the name Ornithinibacillus xuwenensis sp. nov. is proposed.