Spencerozyma acididurans sp. nov., an acid-tolerant basidiomycetous yeast species isolated from acid mine drainage

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 2029 T , by 0.7 % sequence divergence (three gaps and one nucleotide substitution out of 594 bp) in the D1/D2 domains of the LSU rRNA gene and 7.6 % 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.