Candida kantuleensis sp nov., a D-xylose-fermenting yeast species isolated from peat in a tropical peat swamp forest

Three strains (DMKU-XE11(T), DMKU-XE15 and DMKU-XE20) representing a single novel anamorphic and D-xylose-fermenting yeast species were obtained from three peat samples collected from Khan Thulee peat swamp forest in Surat Thani province, Thailand. The strains differed from each other by one to two nucleotide substitutions in the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and zero to one nucleotide substitution in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions showed that the three strains represented a single Candida species that was distinct from the other related species in the Lodderomyces/Candida albicans clade. The three strains form a subclade with the other Candida species including Candida sanyaensis, Candida tropicalis and Candida sojae. C. sanyaensis was the most closely related species, with 2.1-2.4 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 3.8-4.0 % nucleotide substitutions in the ITS region. The three strains (DMKU-XE11(T), DMKU-XE15 and DMKU-XE20) were assigned as a single novel species, which was named Candida kantuleensis sp. nov. The type strain is DMKU-XE11(T) (=CBS 15219(T)=TBRC 7764(T)). The MycoBank number for C. kantuleensis sp. nov. is MB 824179.