RESUMEN
Strain SYSU-17, representing a novel acid-tolerant yeast species which can grow at pH 2.0 weakly, was isolated from acid mine drainage collected in a tailing impoundment of the Fankou Lead/Zinc Mine, Guangdong Province, PR China. Phylogenetic analysis of strain SYSU-17 based on the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit ribosomal RNA (LSU rRNA) gene suggested that strain SYSU-17 was a novel species belonging to the genus Spencerozyma (class Microbotryomycetes, subphylum Pucciniomycotina). It differed from the type strain of the closest related species, Spencerozyma crocea CBS 2029T, by 0.7â% sequence divergence (three gaps and one nucleotide substitution out of 594 bp) in the D1/D2 domains of the LSU rRNA gene and 7.6â% sequence divergence (32 gaps and 22 nucleotide substitutions out of 714 bp) in the ITS region. In contrast to the physiological properties of S. crocea, the novel yeast species was unable to assimilate galactose, d-ribose, xylitol, succinate, d-xylose, ethanol, nitrate and nitrite. The name Spencerozyma acididurans sp. nov. is proposed and SYSU-17 is designated as the holotype.