Abstract

A Gram-stain-negative, ovoid to rod-shaped, aerobic, non-motile bacterial strain, designated YIM 73028T, 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 73028T 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 C18:1?7c, C18:1?7c 11-methyl, C16:0 and C18:0. The genomic DNA G + C content was 65.7%. The average nucleotide identity value between strain YIM 73028T 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 73028T represents a novel species of the genus Tabrizicola, for which the name Tabrizicola caldifontis sp. nov. is proposed. The type strain is YIM 73028T (= KCTC 52713T = CGMCC 1.16151T). © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.