大曲中产酱香芽孢杆菌的筛选及其代谢产香探析

对茅台酒生产各环节所采集的28个样品进行了初步分析，从高温大曲制作过程的不同环节筛选出芽孢杆菌104株，用麦曲模仿升温发酵筛选产香的菌株，经鉴定分别为枯草芽孢杆菌、解淀粉芽孢杆菌、地衣芽孢杆菌等，其中产酱香优良的菌株25株，分为多种香味，与不产香型的细菌对比，产酱香的25株均能产生二乙酰、乙偶姻、蛋白酶、淀粉酶等，结合茅台的生产流程分析了其产香的可能机制，得到结论：芽孢杆菌在大曲发酵过程中产生蛋白酶和淀粉酶等多种酶类和代谢物质，进而在高温、偏酸环境下通过美拉德反应产生吡嗪等多种茅台酒特征香味物质。

Screening of Bacillus sp. from Daqu and Study of Its Metabolites

Preliminary analysis of 28 samples collected in each production procedure of Maotai Liquor was carried out,and then 104 Bacillus sp.strains were screened out in different step during the preparation of high-temperature Daqu,and wheat starter was used for simulated temperature-rising fermentation to screen aroma-producing strains,and these 25 strains which could produce Maotai flavor were identified as Bacillus licheniformis,Bacillus subtilis,B.licheniformis and Bacillus velezensis,compared with other Bacillus sp.strains not producing Maotai flavor,all the 25 strains could produce diacetyl,acetoin,proteinase and amylase etc.Through the analysis of aroma-producing mechanism of Maotai liquor,we may conclude that those Bacillus sp.strains produce varieties of enzymes and metabolites such as protease and amylase etc.at the first step and then those metabolites further produce characteristic flavoring compositions of Maotai liquor such as pyrazine etc.through maillard reaction under high temperature and acidic circumstances.