中高温大曲中芽孢杆菌多样性及代谢特征研究

为探究大曲中芽孢杆菌的代谢特征和功能性，首先采用传统培养法结合分子生物学技术从中高温大曲中分离、鉴定芽孢杆菌，对其微生物多样性进行分析；然后通过耐受性分析从中筛选优势菌，最后利用代谢组学方法分析其代谢特性。结果表明，共分离、鉴定得到49株芽孢杆菌，其中3株芽孢杆菌耐受性较好，分别为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）BA-5、枯草芽孢杆菌（Bacillus subtilis）BS-7和贝莱斯芽孢杆菌（Bacillus velezensis）BV-10。从单菌株及混合菌株发酵后的发酵液中共检测到23种挥发性代谢物和52种非挥发性代谢物，其中，愈创木酚以菌株BS-7单独培养时含量最高，为8.56 mg/L。同时芽孢杆菌混合发酵会增加4-乙烯基愈创木酚的生成量，在菌株BV-10和BA-5混合培养后，达到104.47 mg/L，说明芽孢杆菌单菌株及种间协同作用对白酒酿造中的特征物质形成具有重要影响。

Diversity and metabolic characteristics of Bacillus strains isolated from medium-high temperature Daqu

To explore the metabolic characteristics and functionality of Bacillus strains from Daqu, the Bacillus strains were isolated from medium-high temperature Daqu and identified by traditional culture method coupled with molecular biological technique, and the microbial diversity was analyzed. The dominant strains were screened by tolerance analysis, and their metabolic characteristics were analyzed by metabonomics. The results showed that a total of 49 Bacillus strains were isolated and identified, among which, 3 Bacillus strains had good tolerance, including Bacillus amyloliquefaciens BA-5, Bacillus subtilis BS-7 and Bacillus velezensis BV-10. A total of 23 volatile metabolites and 52 non-volatile metabolites were detected from the fermentation broth of single strain and mixed strains. Among them, the content of guaiacol was the highest when strain BS-7 was under single culture, which was 8.56 mg/L. At the same time, the production of 4-vinylguaiacol was increased by Bacillus mixed fermentation, which reached 104.47 mg/L after the mixed culture of strains BV-10 and BA-5, indicating that single Bacillus strain and the synergistic effect between species had an important effect on the formation of characteristic substances in Baijiu brewing.