米香型白酒小曲发酵酒醅微生物群落演绎与理化因子的相关性

The Correlation between Microbial Community Deduction and Physical and Chemical Factors in Xiaoqu Fermented Grains of Rice Flavor Baijiu

为了探究米香型白酒小曲发酵酒醅微生物群落演绎与理化因子的相关性,分别测定发酵第0,1,2,3,4,5,6,7,8,15,22,29,36,43,50,64,94天的理化指标和微生物群落变化情况。结果表明,在发酵阶段,pH值呈先减小后增加再减小的趋势,发酵结束后pH值约为4.1,总酸则呈逐渐增加的趋势。淀粉含量在发酵前期迅速被水解消耗,发酵后期趋于平缓;还原糖含量在发酵0~2 d内呈增加趋势,在第2天达到最大值约为180.14 g/L,在2~15 d内被微生物利用,其含量迅速降低。在发酵前期(0~3 d)未产生酒精度,发酵22 d时,酒精度达到最大值为9.5°,而发酵后期酒精度降低;总酚含量则随着发酵时间的延长呈现上升趋势,最终发酵结束后含量为375.63 mg GAE/L。在发酵过程中,变形菌门和厚壁菌门为主要优势菌门,主要优势菌属是肠杆菌属、泛菌属、片球菌属和乳球菌属。主坐标分析结果显示:所有样品在PCoA图上分为6个集群,由冗余分析(RDA)可知乳球菌属,假单胞菌属和片球菌属与总酸呈正相关性,泛菌属、阪崎肠杆菌属、肠杆菌属和克雷伯菌属与总酸呈负相关,而泛菌属、阪崎肠杆菌属、肠杆菌属和克雷伯菌属与pH值、淀粉和还原糖呈正相关,且总酸对优势菌属的影响力最大,pH值、淀粉和还原糖对优势菌属的影响较为相似。

In order to explore the change rule of microorganism and physical and chemical factors during the fermentation of rice flavor Baijiu,this experiment measured the physical and chemical indexes and microbial community changes on the 0,1,2,3,4,5,6,7,8,15,22,29,36,43,50,64 and 94 days during the fermentation process.The results showed that during the fermentation stage,pH showed a trend of decreasing first,then increasing and then decreasing,and at the end of fermentation pH was about 4.1,while total acid showed a gradual increase trend.The starch content is rapidly hydrolyzed and consumed in the early stage of fermentation,and tends to be flat in the later stage of fermentation.However,the reducing sugar content shows an increasing trend within 0-2 days of fermentation,reaching a maximum value of about 180.14 g/L on the second day.Within 2-15 days,it is utilized by microorganisms and its content rapidly decreases.In the early stage of fermentation(0-3 d),no alcohol content was generated,at 22 days of fermentation,the alcohol content reached its maximum value of 9.5°,however,in the later stage of fermentation,the alcohol content decreased.The total phenol content showed an increasing trend with the increase of fermentation time,and the final content was 375.63 mg GAE/L at the end of fermentation.In the fermentation process,Proteobacteria and Firmicutes were the main dominant bacteria,and the main dominant bacteria were Enterobacter,Pantoea,Pediococcus and Lactococcus.The results of the principal coordinate analysis showed that all samples were divided into 6 clusters on the PCoA plot,Redundancy analysis(RDA)showed that Lactococcus,Pseudomonas and Pediococcus were positively correlated with total acid composition,Pantoea,Cronobacter,Enterococcus and Klebsiella were negatively correlated with total acid composition.However,Pantoea,Cronobacter,Enterococcus and Klebsiella were positively correlated with pH,starch(St)and reducing sugars(Rs),and total acids had the greatest impact on the dominant bacteria,pH,starch(St)and reducing sugars(Rs)had similar effects on the dominant bacteria.