Abstract

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 degrees C (optimum, 37-45 degrees 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 omega 7c, C-18:1 omega 7c 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)).