汾酒发酵过程中的微生物菌群变化

Microbial Variation during Fenjiu Fermentation

研究采用实时荧光定量聚合酶链式反应(real-time quantitative polymerase chain reaction,qPCR),对发酵过程中的大茬、二茬发酵0、7、15、28 d酒醅样品进行总细菌、总真菌、耐酸乳杆菌、芽孢杆菌和酵母菌的定量分析。分析结果表明汾酒发酵过程中耐酸乳杆菌和酵母为酒醅中的主体微生物,占总细菌和总真菌总和的80%以上。大茬、二茬发酵中,功能微生物在发酵前期(0~7 d)演替规律相似,二茬发酵中后期菌群呈现显著衰亡趋势,且大茬发酵期间各菌群生物量均高于二茬发酵。大茬发酵期间总细菌、耐酸乳杆菌和芽孢杆菌的生物量整体呈上升趋势,分别于28、15、7 d达到最大值(5.53×10^(16)、1.40×10^(13)、1.21×10^(6) copies/g酒醅DNA)。在大茬和二茬发酵中总真菌和酵母的生物量在发酵0~7 d差异不大,呈快速增长趋势,大茬发酵在15 d后至发酵结束逐渐上升至最高值(1.07×10^(15)、1.56×10^(14) copies/g酒醅DNA)。二茬发酵中总真菌和酵母生物量在第7天达到最大值(3.03×10^(14)、1.43×10^(14) copies/g酒醅DNA)。

A real-time quantitative polymerase chain reaction-based method was established to monitor the biomass of bacteria,fungi,Lactobacillus acetotolerans,Bacillus and yeast produced during the Fenjiu fermentation process,including Dacha fermentation and Ercha fermentation,on 0,7,15 d and 28 d.Lactobacillus acetotolerans and total fungi were the primary microbes produced during fermentation and constitute up to 80%of the total microbial population.Similar succession rules of core microbes were observed in the Fenjiu fermentation process.The biomass of bacteria,L.acetotolerans and Bacillus produced during Dacha fermentation was higher than that produced during Ercha fermentation.The biomass of total bacteria,L.acetotolerans and Bacillus increased rapidly in the Dacha fermentation process and reached the maximum on 28,7 d and 15 d,respectively(5.53×10^(16),1.40×10^(13) and 1.21×10^(6) copies/g fermented grain DNA,respectively).However,the biomass decreased significantly in the Ercha fermentation process after 15 d.The biomass of total fungi and Saccharomyces was similar between the Dacha and Ercha fermentation processes during 0-7 d,following which it showed a rapid growth trend and reached the maximum at 28 d of Dacha(1.07×10^(15) and 1.56×10^(14) copies/g fermented grain DNA,respectively).In the Ercha fermentation process,the biomass of total fungi and Saccharomyces reached the maximum value on 7 d(3.03×10^(14) and 1.43×10^(14) copies/g fermented grain DNA,respectively).