Sulfolobus tengchongensis sp nov., a novel thermoacidophilic archaeon isolated from a hot spring in Tengchong, China

A novel thermoacidophilic strain, designated RT8-4, was isolated from an acidic hot spring in Tengchong, Yunnan, China, and characterized phenotypically and phylogenetically. Cells of strain RT8-4 are irregular cocci with peritrechous flagella. The strain grows aerobically in either a lithotrophic or a heterotrophic mode. No anaerobic growth is apparent. Growth on elemental sulfur occurs through the oxidation of sulfur. Strain RT8-4 is capable of utilizing tryptone, D-xylose, D-arabinose, D-galactose, maltose, sucrose, D-fructose, or D-glutamic acid as the sole source of carbon. D-Glucose and D-mannose are not utilized. RT8-4 grows optimally at 85 degreesC and pH 3.5. The G+C content of the genome of RT8-4 is 34.4 mol%. Phylogenetic analysis based on 16S rDNA sequence as well as DNA-DNA hybridization and phenotypic characterization identifies strain RT8-4 as a novel species in the genus Sulfolobus. It is proposed that strain RT8-4 be designated as Sulfolobus tengchongensis sp. nov. The type strain is RT8-4(T).