A heterotrophic acidothermophilic bacterial strain, YNTC-1, was isolated from an acidic hot spring in Tengchong, Yunan, China. YNTC-1 grows at pH value of 1.5-8.0 and temperature of 40-70 degrees C, with optimal pH and temperature at 3.0 and 55 degrees C, respectively. The cells of the strain are in shape of short rod, with 1.0-1.2 mu m in length and 0.7-0.8 mu m in diameter, and with distinct spores at both poles of each cell. The predominant fatty acids in cellular membrane of the strain are C18:1 omega 7c. 16s rRNA gene analysis reveals that this strain is closely related to Alicyclobacillus sendaiensis, with over 99% sequence similarity. Based on phenotypic and genotypic analyses, YNTC-1 is identified as a member of A. sendaiensis. Considering some important morphological and biochemical differences between strain YNTC-1 and A. sendaiensis ATCC 27009(T), YNTC-1 may be proposed to be a novel subspecies of A. sendaiensis. However, this viewpoint has to be confirmed by further studies. Co-bioleaching of pyrite and chalcopyrite with strain YN22, Sulfobacillus thermosulfidooxidans, shows that strain YNTC-1 has no evident influence on bioleaching rates of these two sulphide minerals.