Baijiu (Chinese liquor) is a type of traditional distilled alcoholic beverage produced through spontaneous solid-state fermentation with sorghum as the primary material. Material processing, including sorghum soaking, steaming and cooling which is carried out in an open environment, is an integral part of Baijiu manufacturing. However, the microbiota involved in material pretreatment and its associate with the alcoholic fermentation is unclear. This research is aimed to exploring the diversity and role of microbiota during material pretreatment of light-flavor Baijiu. Results showed that Cyanobacteria, Epicoccum, and Cladosporium predominated in the sorghum at the beginning of soaking. Lactobacillus and Pichia became the predominant bacterial and fungal genera by the end of soaking. With the dynamics of microbiota, the pH declined sharply and the categories and concentration of volatile flavors such as alcohols, esters, acids, phenols, ketones, and aldehydes increased. Correlation analysis indicated that Lactobacillus and Pichia showed positive correlation with various flavors during soaking. Furthermore, SourceTracker analysis revealed that the microbiota involved during cooling processing was an important source of the Lactobacillus during fermentation of light-flavor Baijiu. This study illustrates the role of microbiota during material pretreatment and the association with alcoholic fermentation, which contributes to reveal the mechanism of Baijiu manufacturing.

白酒（白酒）是通过以高粱为主要原料的自发固态发酵生产的一种传统蒸馏酒精饮料。材料加工，包括在露天环境中进行的高粱浸泡，蒸煮和冷却，是白酒制造不可或缺的一部分。但是，尚不清楚参与材料预处理的微生物群及其与酒精发酵的关系。本研究旨在探讨淡味白酒材料预处理过程中微生物群的多样性和作用。结果表明，在浸泡开始时，高粱中主要存在蓝细菌，淫羊Cl和枝孢菌。浸泡结束后，乳酸杆菌和毕赤酵母成为细菌和真菌的主要属。随着微生物群的动力学，pH急剧下降，挥发性调味剂（如醇，酯，酸，酚，酮和醛）的种类和浓度增加。相关分析表明，乳酸菌和毕赤酵母在浸泡过程中与多种风味呈正相关。此外，SourceTracker分析表明，冷却过程中涉及的微生物群是淡味白酒发酵过程中乳酸菌的重要来源。。这项研究说明了微生物菌群在材料预处理过程中的作用以及与酒精发酵的关系，这有助于揭示白酒制造的机理。