Thermorhabdus hydrogeniformans gen. nov., sp. nov., a thermophilic anaerobic bacterium from hot spring sediments in Tengchong, Yunnan, China.

A novel member of the phylum Bacillota was isolated from Tengchong Hot Spring sediments (Yunnan, China). Cells are Gram-stain-negative, anaerobic, rod-shaped bacteria (0.3-0.5 µm wide and 1.5-3.5 µm long) and flagellated. Optimal growth occurs anaerobically at 60 °C (range 50-70 °C), pH 7.0 (range 6.0-8.0) and 0 g l-1 NaCl (range 0-50 g l-1). Substrate utilization encompassed cellobiose, sucrose, soluble starch, casein, glucose, xylan, ethanol, ribose, yeast extract, mannose and tryptone. Comparative 16S rRNA gene-sequence analysis revealed 93.6% similarity to Biomaibacter acetigenes SK-G1T. The genome is 2.86 Mbp with a DNA G+C content of 46.5 mol%. Phylogenetic analyses based on the 16S rRNA gene and the whole genome placed strain DL9XJH-110T within the family Tepidanaerobacteraceae. The predominant cellular fatty acids (>10%) were C15 : 0, iso-C15 : 0, C16 : 0 and C14 : 0. Phenotypic, phylogenetic and chemotaxonomic properties indicate that strain DL9XJH-110T represents a novel species in a new genus, for which the name Thermorhabdus hydrogeniformans gen. nov., sp. nov. is proposed. The type strain is DL9XJH-110T (=CCAM 2419T=JCM 39573T).