Abstract: In this study, high-throughput sequencing and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were employed to determine the microbial diversity and flavor substances in Jiupei at 0, 3, 6, 9, 12, 15, 20, 25, 30, 40, 50, and 60 days of fermentation. The results indicated that the yeast flora accounted for 43.24% of the total relative abundance of the microbial communities during Jiupei fermentation, consisting of 49 yeast genera including Kazachstania, Saccharomyces, Pichia, Saccharomycopsis, Debaryomyces, Trichosporon, and Wickerhamomyces. The succession of yeast flora during Jiupei fermentation was mainly driven by biological factors such as Lactobacillus, Thermomyces, Kroppenstedtia, Weissella, Saccharopolyspora, and Aspergillus, as well as non-biological factors such as moisture, starch, temperature, and alcohol contents. The yeast flora was significantly associated with 25 volatile flavor substances (P < 0.05), and affected the synthesis of volatile flavor substances including esters (such as ethyl hexanoate, ethyl acetate, butyl hexanoate, and propyl hexanoate), alcohols (such as ethanol, isopentanol, phenylethanol, 1-octanol, and 1-nonanol), and ketone more than other metabolites such as acid, phenol, and aldehyde. This study reveals the regulatory mechanism and metabolic characteristics of yeast community succession during the fermentation process of Jiupei for Nongxiangxing Baijiu, providing scientific support for the optimization of Baijiu flavor and technological innovation.

Key words: Nongxiangxing Baijiu; Jiupei; yeast flora; drivers; volatile flavor substances