浓香型大曲中功能性酵母菌的筛选、鉴定及发酵特性研究

以浓香型大曲为研究对象，采用稀释涂布平板法从中分离酵母菌，对其形态特征进行观察；采用2,3,5-氯化三苯基四氮唑（TTC）显色法初筛，通过发酵力、产酒能力、耐高温、耐酒精能力实验进行复筛，筛选一株优良的功能性酵母菌，利用Biolog微生物自动分析系统对其进行鉴定，并利用顶空固相微萃取气质联用（HS-SPME-GC-MS）法对其液态发酵产物进行分析。结果表明，从浓香型大曲中共分离出9株酵母菌，其中菌株NDY-06性能最突出，可耐受42 ℃的高温，16%vol的酒精度，且具有一定的发酵产酒能力；该菌株被鉴定为产香酵母Zygosaccharomyces cidri，从其液态发酵产物中共检测到35种挥发性风味物质，包括醇类物质7种，酯类物质13种，酸类物质7种，吡嗪类物质3种，对白酒香气成分有一定的贡献。

Screening,identification and fermentation characteristics of functional yeast from strong-flavor Daqu

Using strong-flavor Daqu as research object, the yeast strains were isolated from strong-flavor Daqu by dilution coating plate method, and their morphological characteristics were observed. An excellent and functional yeast strain was obtained by preliminary screening with 2,3,5-triphenyltetrazolium chloride (TTC) color-developing method and rescreening with fermentation capacity, alcohol production capacity, high temperature tolerance and alcohol tolerance tests. The strain was identified by Biolog automatic microbial analysis system, and the liquid state fermentation products were analyzed by HS-SPME-GC-MS. The results showed that 9 strains of yeast were isolated from strong-flavor Daqu, among which the strain NDY-06 had the most outstanding performance, which could tolerate high temperature 42 ℃ and alcohol content 16%vol, and had a certain alcohol-producing ability by fermentation. The strain was identified as Zygosaccharomyces cidri. A total of 35 volatile flavor substances were detected in the products with the liquid state fermentation, including 7 alcohols, 13 esters, 7 acids and 3 pyrazines, indicating the strain had a certain contribution to the aroma components of Baijiu.