【摘要】 该研究从浓香型白酒大曲中分离筛选产α-淀粉酶菌株，通过形态学观察及分子生物学技术对筛选菌株进行鉴定，并探究了不同发酵温度和初始水分含量对筛选菌株固态发酵过程中生长、代谢产α-淀粉酶和挥发性风味物质的影响，并进行挥发性风味物质差异和代谢通路富集分析。结果表明，分离筛选得到一株产α-淀粉酶的菌株L-3，其被鉴定为贝莱斯芽孢杆菌（Bacillus velezensis）。初始水分含量40%、发酵温度40℃条件下最适合菌株L-3生长，发酵4 d时菌数最多，为1.08×10¹¹ CFU/g；初始水分含量40%、发酵温度50℃条件下淀粉酶活力最高，发酵4 d时酶活可达（128.64±1.191）U/g，更有利于挥发性风味物质的合成。基于差异风味物质通路富集结果，最适菌株L-3生长的初始水分含量40%、发酵温度40℃条件下，甘油磷脂代谢通路显著富集，乙醛的合成与通向丙酮酸代谢和糖异生的转化在此通路中进行，其显著富集可能与乙醛在该温度下的大量合成有关。更多还原

【Abstract】 In this study, α-amylase-producing strains were isolated and screened from strong-flavor（Nongxiangxing） Baijiu Daqu, the screened strains were identified by morphological observation and molecular biological technique. The effects of different fermentation temperatures and initial moisture contents on the growth, metabolism, production of α-amylase and volatile flavor substances in the solid-state fermentation process of the screened strains were investigated, and the differences and metabolic pathways enrichment of volatile flavor substances were analyzed. The results showed that a α-amylase-producing strain L-3 was isolated and screened, and identified as Bacillus velezensis. Under the conditions of initial water content 40% and fermentation temperature 40 ℃, the strain L-3 was the most suitable for growth, and the maximum number of bacteria reached 1.08×10¹¹ CFU/g at 4 d of fermentation. The highest activity of amylase reached（128.64±1.191） U/g when the initial moisture content was 40% and the fermentation temperature was 50 ℃, and it was more conducive to the synthesis of volatile flavor substances. Based on the enrichment results of the differential flavor substance pathway, the glycerophospholipid metabolic pathway was significantly enriched under the condition of initial water content 40% and fermentation temperature 40 ℃ for the optimal strain L-3. Acetaldehyde synthesis and the transformation to pyruvate metabolism and gluconeogenesis took place in this pathway, and its significant enrichment might be related to the large amount of acetaldehyde synthesis at this temperature.更多还原