Abstract: The structure and diversity of cultural yeast populations in different Maotai-flavor liquor brewing regions of Maotain town, Guizhou province were studied. Yeast samples were collected from the brewing environment and the fermentation starter, Daqu. A total of 568 yeast strains were obtained and identified by 26S rDNA gene sequencing, 334 of which came from the brewing environment and identified as 25 species and 1 uncultured yeast strain in 14 genera, while the remaining 223 were derived from Daqu were identified as 20 species and 1 uncultured fungal strain in 12 genera. Ten yeast populations were common to both. The dominant species in the environment were Wickerhamomyces anomalus, Saccharomyces cerevisiae and Hyphopichia burtonii while those in Daqu were W. anomalus and Saccharomycopsis fibuligera. The diversity of yeast in the environment and Daqu was significant quantitatively but at the species level. To our knowledge, this study is the first to isolate Nectaromyces rattus, Wickerhamomyces sp. H1Y23, Issatchenkia sp. S612Y5, Wickerhamomyces pijperi, Trichosporon faecale, Kazachstania sp. IMB190R, Pseudozyma sp., Kazachstania solicola, Torulaspora sp. Z8Y10 and Helicoceras oryzae from the Maotai-flavor liquor brewing process.

Key words: Maotai-flavor liquor, environmental samples from brewing regions, Daqu, yeast population structure diversity