Gong Lijuan, Qin Shuai, Zheng Xinrong, Zhao Jinsong, Liu Minmin, Zhao Minhui
College of Biological Engineering, Sichuan University of Science & Engineering, Yibin 644000, China.
Sichuan Province Engineering Technology Research Center of Liquor-Making Grains, Yibin 644000, China.
Food Chem X. 2025 Feb 27;27:102321. doi: 10.1016/j.fochx.2025.102321. eCollection 2025 Apr.
Maotai-flavor Daqu is an indispensable and important fermentative and saccharifying agent in the production of Chinese sauce-flavored baijiu. The diversity and complexity of its microbial community has a decisive impact on the quality and flavor of the baijiu. However, although some studies have provided preliminary analysis of the microbial composition in Daqu, the specific influence of environmental microbes on the Daqu production process, as well as the origin and formation mechanism of the Daqu microbial community, are still not clear. In addition, the production process of Daqu is an open natural fermentation process. Microorganisms from the environment can enter Daqu through various pathways such as air, soil, and raw materials, thereby affecting its microbial community structure. To investigate the source of the microbial community in Maotai-flavor Daqu and the impact of environmental microorganisms on the Daqu production process, air was collected from inside and outside the Daqu room, soil from the external environment, Daqu wheat, rice straw, and Daqu at different stages. High-throughput sequencing was used to detect bacteria and fungi in all samples. Finally, with Daqu at different periods as the target for tracing and the other samples as the objects for tracing, Source Tracker was employed to conduct a tracing analysis of Daqu. The results showed that the richness and diversity of microorganisms in the samples decreased gradually from the outside to the inside. The microbial community structure in the soil in the external environment was quite different from that of other samples, and its contribution to the community in Daqu was small. Qu wheat and rice straw made a great contribution to Daqu. The findings of this study show that the environment and raw materials affect the quality of Daqu, and the change in microflora in the fermentation process of Daqu is determined by both the environment and raw materials.
酱香型大曲是中国酱香型白酒生产中不可或缺的重要发酵剂和糖化剂。其微生物群落的多样性和复杂性对白酒的品质和风味具有决定性影响。然而，尽管一些研究对大曲中的微生物组成进行了初步分析，但环境微生物对大曲生产过程的具体影响以及大曲微生物群落的起源和形成机制仍不明确。此外，大曲的生产过程是一个开放式的自然发酵过程。环境中的微生物可通过空气、土壤和原料等多种途径进入大曲，从而影响其微生物群落结构。为了探究酱香型大曲微生物群落的来源以及环境微生物对大曲生产过程的影响，采集了大曲房内外的空气、外部环境的土壤、大曲小麦、稻草以及不同阶段的大曲。采用高通量测序技术检测所有样品中的细菌和真菌。最后，以不同时期的大曲为溯源对象，以其他样品为被溯源对象，利用Source Tracker对大曲进行溯源分析。结果表明，样品中微生物的丰富度和多样性从外到内逐渐降低。外部环境土壤中的微生物群落结构与其他样品差异较大，其对大曲群落的贡献较小。曲麦和稻草对大曲贡献较大。本研究结果表明，环境和原料影响大曲品质，大曲发酵过程中微生物区系的变化由环境和原料共同决定。
