Strain of lactic-acid-stress-tolerant zygosaccharomyces bailii capable of achieving high-yield production of ethanol and flavor compounds

Application of Zygosaccharomyces bailii CCTCC NO:

• M 2023729 or a microbial agent containing the Zygosaccharomyces bailii CCTCC NO:
• M 2023729, wherein the application is one or more of the following:
• degradation of lactic acid, increase in an ethanol content, and increase in contents of flavor compounds, and the application comprising the following steps:
• inoculating a single colony of the Zygosaccharomyces bailii CCTCC NO:
• M 2023729 into a sorghum juice medium, and culturing at 30° C. and 200 rpm for 24 hours to obtain a seed culture, and inoculating 1 mL of the seed culture of the Zygosaccharomyces bailii CCTCC NO:
• M 2023729 into 100 mL of a fermentation medium added with 40 g/L lactic acid, and culturing at 30° C. and 200 rpm for 72 hours;
• wherein the sorghum juice medium is prepared by soaking sorghum in water at a ratio of 1:4 (M/V) overnight, adding amylase for steaming and liquefaction, adding glucoamylase for saccharification at 60° C., performing filtration and centrifugation, and adjusting a sugar content to 5° Bx.;
• and the fermentation medium is prepared by adjusting a pH value of the sorghum juice medium to 3.2 using lactic acid.

Application of a yeast agent in Baijiu (Chinese liquor) brewing, comprising:

• inoculating Zygosaccharomyces bailii CCTCC NO:
• M 2023729 into a seed culture medium to obtain a seed culture;
• centrifuging the seed culture to remove a supernatant, and resuspending precipitate in water to obtain the yeast agent;
• wherein
• the yeast agent is applied to a fourth fermentation round of a Maotai-flavor liquor brewing process, with steps as follows:
• distilling, spreading and cooling a fermented grain, mixing the cooled fermented grain with Qu, a Chinese fermentation starter, taking out the fermented grain, evenly spraying the yeast agent onto the fermented grain, and mixing thoroughly;
• and placing the mixed fermented grain into a bamboo basket, and placing in a fermentation pile and a fermentation pit for fermentation under in-situ conditions.