Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology & Business University (BTBU), Beijing 100048, China; Beijing Engineering and Technology Research Center of Food Additives, Beijing 100048, China.
Beijing Engineering and Technology Research Center of Food Additives, Beijing 100048, China.
Food Res Int. 2020 Mar;129:108837. doi: 10.1016/j.foodres.2019.108837. Epub 2019 Dec 9.
Fortification of Daqu with isolated functional strains can influence the metabolic activity of the microbial community, and thus alter the flavors of the Baijiu produced with Daqu as a fermentation starter. Here, we analyzed the microbial community dynamics of, and volatile compound production by, Daqu fortified respectively with three high-yield ethyl caproate-producing yeasts (Saccharomyces cerevisiae Y7#09, Hyphopichia burtonii F12507 and Clavispora lusitaniae YX3307), or with a mixture of these three strains, during the fermentation of Baijiu. The microbial community was investigated using Illumina HiSeq technology. Three bacterial genera (Bacillus, Lactobacillus and Enterobacter) and four fungal genera (Pichia, Clavispora, Saccharomyces and Saccharomycopsis) were dominant in the microbial communities. The volatile compounds were examined by gas chromatography-mass spectrometry. Forty-one flavor compounds were detected in all samples, including seven alcohols, 26 esters and four aldehydes. In particular, an increase in ethyl caproate content was associated with Daqu fortified with S. cerevisiae Y7#09, C. lusitaniae YX3307, or the mixed inoculum. The ester content of these fortified Daqu was higher in the later stage of the fermentation than that in unfortified Daqu, or in Daqu fortified with H. burtonii F12507. Our results show that fortification of Daqu with aroma-producing yeast strains influenced the microbial community composition in the Daqu and affected its metabolic activity. Overall, this study reveals the features of fortified Daqu microbial communities in different phases and improves understanding of the relationships between aroma-producing yeast and the metabolic activity of microbial communities in Baijiu production.
大曲的强化可以影响微生物群落的代谢活性，从而改变以大曲为发酵剂生产的白酒的风味。在这里，我们分析了分别用三种高产己酸乙酯酵母（酿酒酵母 Y7#09、毕赤酵母 F12507 和酒香酵母 YX3307）或这三种菌株的混合物强化的大曲在白酒发酵过程中的微生物群落动态和挥发性化合物的产生。使用 Illumina HiSeq 技术研究微生物群落。在微生物群落中，三个细菌属（芽孢杆菌属、乳杆菌属和肠杆菌属）和四个真菌属（毕赤酵母属、酒香酵母属、裂殖酵母属和假丝酵母属）占优势。通过气相色谱-质谱法检查挥发性化合物。在所有样品中均检测到 41 种风味化合物，包括 7 种醇、26 种酯和 4 种醛。特别是，己酸乙酯含量的增加与用酿酒酵母 Y7#09、酒香酵母 YX3307 或混合接种物强化的大曲有关。与未强化大曲或用毕赤酵母 F12507 强化的大曲相比，这些强化大曲的酯含量在发酵后期更高。我们的结果表明，用产香酵母菌株强化大曲影响了大曲中的微生物群落组成，并影响了其代谢活性。总的来说，本研究揭示了不同阶段强化大曲微生物群落的特征，提高了对产香酵母与白酒生产中微生物群落代谢活性之间关系的认识。
