f.a., sp. nov., a novel yeast species isolated from Thai traditional fermented food.

Seven yeast strains (UBIF12-1, UBFB13-1, SRFS56-3, SRFS57-2, SKFS62-1, SKFS66-1 and SKFS67-1) representing a single anamorphic novel yeast species were isolated from traditional Thai fermented foods in Ubon Ratchathani, Surin and Sisaket in the northeast part of Thailand. The results of analysis of the sequences of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region indicated that the seven strains showed zero to one nucleotide substitutions in the sequences of the D1/D2 region of the LSU rRNA gene, and zero to four nucleotide substitutions in the ITS region. CBS 5658 was the most closely-related species, but with 0.7-0.9% nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 2.0-2.2% nucleotide substitution in the ITS region. The results of a phylogenetic analysis based on the concatenated ITS and D1/D2 regions confirmed that the seven strains represented a single species of the genus distinct from the other recognized species of the genus. Furthermore, the morphological, biochemical and physiological properties of the seven strains not only indicated that they represented members of the genus , but that they were separated from and the two most closely related species in the phylogenetic tree. Therefore, the seven strains were identified as representing a novel species, for which we propose the name f.a., sp. nov. The holotype is TBRC 15053 (isotype: SRFS57-2 and PYCC 9021). The MycoBank number of the novel species is 841892.