[关键词]
[摘要]
本文研究了酱香型酒醅中的产香芽孢杆菌及其优势代谢产物。通过平板分离法从酱香型酒醅中筛选出5株芽孢杆菌,采用PLFA技术对其鉴定,分别为:蜡样芽孢杆菌(Bacillus ereus)、泛酸枝芽孢杆菌(Virgibacillus pantothenticus)、巨大芽孢杆菌(Bacillus megaterium)、枯草芽孢杆菌(Bacillus subtilis)和地衣芽孢杆菌(Bacillus licheniformis);革兰氏染色试验结果说明:这五类菌株均为革兰氏阳性菌;生化分析发现:枯草芽孢杆菌产淀粉酶能力最强,巨大芽孢杆菌蛋白质水解能力最强;以高粱粉为底物进行固态发酵,采用GC-MS分析技术对发酵代谢产物进行分析表明:菌株的优势产物主要为3-羟基-2-丁酮,另外还有少量的2,3-丁二醇和酯类等芳香物质。蜡样芽孢杆菌、泛酸枝芽孢杆菌、巨大芽孢杆菌、枯草芽孢杆菌和地衣芽孢杆菌这五类菌株是酱香型白酒主要的产香功能菌。
[Key word]
[Abstract]
Aroma-producing Bacillus spp. and their major metabolites from Maotai-flavor fermented grains were investigated in this study. Five Bacillus strains were isolated from Maotai-flavor fermented grains using the plate dilution method. Phospholipid fatty acid (PLFA) analysis was adopted to identify the strains, which were Bacillus cereus, Virgibacillus pantothenticus, Bacillus megaterium, Bacillus subtilis, and Bacillus licheniformis. Gram staining revealed that the strains were all gram-positive bacteria. Biochemical analysis indicated that Bacillus cereus exhibited the highest amylase-producing capacity, while Bacillus megaterium exhibited the highest protein hydrolysis capacity. Solid state fermentation was performed using local sorghum powder as a substrate, and metabolites were detected by gas chromatography-mass spectrometry (GC-MS). The results showed that 3-hydroxy-2-butanone was the major product, and a small quantity of aromatic compounds, such as 2,3-butanediol and esters, was also detected. The flavor-producing Bacillus strains in the grains were mainly Bacillus cereus, Virgibacillus pantothenticus, Bacillus megaterium, Bacillus subtilis, and Bacillus licheniformis.
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[基金项目]
国家固态酿造工程技术研究中心开放课题(2015k-246);酿酒生物技术及应用四川省重点实验室开放基金项目(NJ2014-16);四川理工学院人才引进项目(2014RC28)