Abstract：
Ethyl hexanoate and ethyl butyrate are indispensable flavor metabolites in strong-flavor Baijiu (SFB), but batch production instability in fermenting grains can reduce the quality of distilled Baijiu. Biofortification of the fermentation process by designing a targeted microbial collaboration pattern is an effective method to stabilize the quality of Baijiu. In this study, we explored the metabolism under co-culture liquid fermentation with Clostridium tyrobutyricum DB041 and Saccharomyces cerevisiae YS219 and investigated the effects of inoculation with two functional microorganisms on physicochemical factors, flavor metabolites, and microbial communities in solid-state simulated fermentation of SFB for the first time. The headspace solid-phase microextraction-gas chromatography-mass spectrometry results showed that ethyl butyrate and ethyl hexanoate significantly increased in fermented grain. High-throughput sequencing analysis showed that Pediococcus, Lactobacillus, Weissella, Clostridium_sensu_stricto_12, and Saccharomyces emerged as the dominant microorganisms at the end of fermentation. Co-occurrence analysis showed that ethyl hexanoate and ethyl butyrate were significantly correlated (|r| > 0.5, P < 0.05) with a cluster of interactions dominated by lactic acid bacteria (Pediococcus, Lactobacillus, Weissella, and Lactococcus), which was driven by the functional C. tyrobutyricum and S. cerevisiae. Mantel test showed that moisture and reducing sugars were the main physicochemical factor affecting microbial collaboration (|r| > 0.7, P < 0.05). Taken together, the collaborative microbial pattern of inoculation with C. tyrobutyricum and S. cerevisiae showed positive results in enhancing typical flavor metabolites and the synergistic effects of microorganisms in SFB.
摘要：
己酸乙酯和丁酸乙酯是强风味白酒(SFB)中不可缺少的风味代谢产物,但是发酵谷物的批量生产不稳定会降低蒸馏白酒的质量。通过设计有针对性的微生物协作模式对发酵过程进行生物强化是稳定白酒质量的有效方法。在这项研究中,我们探索了与酪丁酸梭菌DB041和酿酒酵母YS219共培养液体发酵下的代谢，并研究了接种两种功能微生物对理化因子的影响，风味代谢物，和微生物群落在SFB固态模拟发酵中的首次应用。顶空固相微萃取-气相色谱-质谱分析结果表明,发酵谷物中丁酸乙酯和己酸乙酯显著增加。高通量测序分析表明,乳酸菌,Weissella,发酵结束时，梭状芽孢杆菌_sensu_stricto_12和酵母属作为主要微生物出现。共现分析表明，己酸乙酯和丁酸乙酯具有显着相关（|r|>0.5，P<0.05），并具有以乳酸菌（片球菌，乳酸菌,Weissella,和乳球菌），这是由功能性的酪丁酸梭菌和酿酒酵母驱动的。Mantel试验表明,水分和还原糖是影响微生物协同的主要理化因子(|r|>0.7,P<0.05)。一起来看,用酪丁酸梭菌和酿酒酵母接种的协同微生物模式在增强SFB中的典型风味代谢产物和微生物的协同作用方面显示出积极的结果。
