Dynamic profile of yeast community associated with urea metabolism in Chinese light-aroma liquor fermentation

Abstract:

[Objective] This study was to explore the structure and dynamic of yeast community, and to analyze the potential key yeast species associated with urea metabolism and its regulation by environmental factors. It could provide potential clues for reducing ethyl carbamate in Chinese light-aroma liquor fermentation process. [Methods] The main precursor and microbial groups were identified by correlation analysis, and yeast community was revealed by high-throughput sequencing. Besides, the potential key species related with the urea metabolism were predicted by partial least squares regression. In addition, the effect of environmental factors on yeast community was analyzed by redundancy analysis. [Results] Urea was identified as the main precursor, and was associated with yeast population in Chinese light-aroma liquor fermentation. A total of 22 yeast species was identified by high-throughput sequencing at 97% sequence similarity. Hanseniaspora osmophila, Pichia fermentans and Saccharomyces cerevisiae were positively associated with urea formation, while Pichia kudriavzevii was positively associated with urea degradation. In addition, moisture, pH, ethanol and arginine were important environmental factors which associated with yeast community during liquor fermentation process. [Conclusion] Environmental factors could influence the potential key yeast species, which could provide strategies to decrease urea and ethyl carbamate in Chinese light-aroma liquor fermentation.