Diversity of yeast species during fermentative process contributing to Chinese Maotai-flavour liquor making

AIMS: The famous traditional Chinese Maotai-flavour liquor is produced by a unique spontaneous simultaneous saccharification and fermentation process, which contributes to a distinctive yeast community with specific physiological properties and performances. Therefore, it would be useful to investigate this yeast community and reveal the novelty of its characteristics. METHODS AND RESULTS: Nine yeast species were obtained from the fermentation period. A combination of physiological and functional analyses revealed a very high diversity of yeast populations. In particular, the extremely high temperature and low acidity of the fermentation conditions led to an accumulation of species with distinctive heat- and acid-resistant properties. Moreover, these yeast species were also significant flavour contributors, for various alcohols, acids and esters. CONCLUSIONS: The Chinese Maotai-flavour liquor-fermentation process is rich in yeast resources with distinctive fermentation properties, which were different from other beverages. SIGNIFICANCE AND IMPACT OF THE STUDY: This work is the first to study the complex yeast ecology of the Maotai-flavour liquor-making process. It allows a deeper insight into the mechanism of this process.