School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing, 100048, China.
Arch Microbiol. 2021 Nov;203(9):5831-5839. doi: 10.1007/s00203-021-02552-8. Epub 2021 Sep 7.
Daqu provides enzymes and precursors for liquor fermentation, and is the core of liquor fermentation. In this study, 11 Bacillus strains were isolated from sesame-flavored liquor Daqu, which can not only produce protease and amylase, but also have antagonistic effects on common pathogens Escherichia coli and Staphylococcus aureus. According to the gyrA gene phylogeny analysis, these 11 Bacillus strains belong to three species, B1, Y14, Y15, and YPDW9 belong to Bacillus mojavensis, W7, W13, YPDW6, and YPDW12 belong to Bacillus subtilis, and W14, Y5, and YPDW1 belong to Bacillus velezensis. According to the results of random amplified polymorphic DNA (RAPD) typing, there are three strains in Bacillus mojavensis, among which Y14 and Y15 are the same ones. All four Bacillus subtilis strains and three Bacillus velezensis strains are different. The specific primers were used to randomly amplify the biological control genes expressing lipopeptide antibiotics (bioA, bmyB, ituC, fenD, srfAA, srfAB, yngG,and yndJ), and the results showed that antagonistic genes other than fenD gene were amplified in four Bacillus mojavensis strains; Bacillus subtilis amplification was significantly different, but srfAA, bmyB and yndJ genes were all present; All genes were amplified in Bacillus velezensis except YPDW1 without ituC. This research provides new ideas for strengthening Daqu and lays a foundation for improving the quality of liquor.
大曲为白酒发酵提供了酶和前体物质，是白酒发酵的核心。本研究从芝麻香型白酒大曲中分离得到 11 株芽孢杆菌，它们不仅能产蛋白酶和淀粉酶，而且对大肠杆菌和金黄色葡萄球菌等常见病原菌具有拮抗作用。根据 gyrA 基因系统发育分析，这 11 株芽孢杆菌分属于 3 个种，B1、Y14、Y15 和 YPDW9 属于莫海威芽孢杆菌，W7、W13、YPDW6 和 YPDW12 属于枯草芽孢杆菌，W14、Y5 和 YPDW1 属于解淀粉芽孢杆菌。根据随机扩增多态性 DNA（RAPD）分型结果，莫海威芽孢杆菌有 3 个菌株，其中 Y14 和 Y15 为同一菌株。4 株枯草芽孢杆菌和 3 株解淀粉芽孢杆菌菌株均不同。使用特异性引物随机扩增表达脂肽类抗生素的生物防治基因（bioA、bmyB、ituC、fenD、srfAA、srfAB、yngG 和 yndJ），结果显示 4 株莫海威芽孢杆菌中均扩增到除 fenD 基因外的拮抗基因；枯草芽孢杆菌扩增结果差异显著，但均存在 srfAA、bmyB 和 yndJ 基因；除 YPDW1 无 ituC 基因外，解淀粉芽孢杆菌均扩增到所有基因。本研究为强化大曲提供了新的思路，为提高白酒质量奠定了基础。
