Tabrizicola caldifontis sp. nov., Isolated from Hot Spring Sediment Sample

A Gram-stain-negative, ovoid to rod-shaped, aerobic, non-motile bacterial strain, designated YIM 73028^T, was isolated from a sediment sample collected from a hot spring in Tibet, China. Phylogenetic analysis (based on the 16S rRNA gene sequences) indicated that strain YIM 73028^T belongs to the genus Tabrizicola and showed the highest sequence similarity to the type strain of Tabrizicola aquatica (97.0%). Growth occurred at 30-50 °C (optimum, 37-45 °C) and pH 6.5-8.5 (optimum, pH 7.0-7.5). The respiratory isoprenoid quinone was ubiquinone Q-10. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, unidentified amino lipid and unidentified lipid. The major cellular fatty acids (> 10%) were C_18:1 ω7c, C_18:1 ω7c 11-methyl, C_16:0 and C_18:0. The genomic DNA G + C content was 65.7%. The average nucleotide identity value between strain YIM 73028^T and type species of Tabrizicola aquatica was lower than 95-96% threshold recommended for distinguishing novel prokaryotic species. Based on the phenotypic, physiological, chemotaxonomic, genotypic, and phylogenetic data, strain YIM 73028^T represents a novel species of the genus Tabrizicola, for which the name Tabrizicola caldifontis sp. nov. is proposed. The type strain is YIM 73028^T (= KCTC 52713^T = CGMCC 1.16151^T).