Abstract: Light-flavor baijiu is one of the four basic baijiu aromas, and the succession and metabolism of the microbial community during the fermentation process is closely related to physical and chemical factors. Fermentation temperature is one of the most important factors. In this study, the fermentation process of light-flavor baijiu at two different initial temperatures（7.5±1 ℃、15.5±1 ℃）was analyzed using Illumina Miseq sequencing and gas chromatography-mass spectrometry (GC-MS). The results showed that there were significant differences (P < 0.05) in the acidity of fermented grains at different initial temperatures; the higher initial temperatures accelerated the growth of the relative abundance of Lactobacillus and Saccharomyces in the fermented grains; a total of 62 volatile compounds were detected in the fermented grains, and 12 important compounds were identified as contributing to the organoleptic differences in the raw baijiu. Lactobacillus and Saccharomyces were significantly and positively correlated with ethyl acetate, ethyl lactate, ethyl 3-phenylpropionate, furfuryl alcohol, ethyl caprate, ethyl butyrate, isoamyl acetate, and isobutyl alcohol and were the key microorganisms contributing to the formation of differential compounds. By changing the initial fermentation temperature, the microbial community structure and volatile compound composition during the fermentation of light-flavor baijiu can be effectively regulated, and this study is of great value in guiding the quality control and management strategies during the fermentation process.

Key words: baijiu, microbial communities, temperature, Lactobacillus, Saccharomyces