Abstract:Traditional Baijiu brewing is an open fermentation process，and the microbial community succession and metabolic activities during brewing are easily affected by external environment. Therefore，to address these issues，it is feasible to isolate and select core functional microbial strains with high tolerance and apply them in production. In this paper，nine yeast strains with high tolerance were selected from the fermented grains of sauce-flavor Baijiu under dual stress conditions of high temperature and high acid，which were identified as Zygosaccharomyces bailii.The fermentation and flavor compound synthesis of these strains were characterized by simulating Baijiu fermentation. The results showed that strain BM09 had outstanding growth performance under 37 ℃，16 g∕L acetic acid，110 g∕L lactic acid and 14% ethanol，with high ethanol and ester production capacity. Therefore，it was used as an enhancing strain in the actual production of sauce-flavor Baijiu.In situ fermentation indicated that BM09 improved the raw material utilization of sauce-flavor Baijiu in the seventh round by 29.80%，increased the ethanol yield by 63.10% and ethyl acetate by 85.17%，while reduced acetaldehyde by 70.37%.