中高温大曲发酵过程中曲皮、曲心微生物群落的差异性和变化规律

Difference and change rule of microbial community in the Qupi and Quxin of medium-high temperature Daqu during fermentation process

中高温大曲是浓香型白酒发酵体系中微生物的重要来源,该研究采用高通量测序技术,结合理化指标测定,对中高温大曲发酵过程中曲皮、曲心微生物群落的差异性和变化规律进行解析。结果表明,发酵过程曲心水分含量、酸度和温度均高于曲皮;曲皮微生物多样性和丰富度指数总是高于曲心;曲皮和曲心主要优势菌一致,但优势菌的变化规律差异较大。厚壁菌门(Firmicutes)、放线菌门(Actinobacteriota)和变形菌门(Proteobacteria)为曲皮和曲心的优势细菌门,且Firmicutes相对丰度在曲皮发酵前期上升先于曲心;子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、毛霉菌门(Mucoromycota)为曲皮和曲心的优势真菌门,且子囊菌门在曲心发酵过程相对丰度略高于曲皮;曲皮和曲心主要优势细菌属有高温放线菌属(Thermoactinomyces)、乳杆菌属(Lactobacillus)和糖多孢菌属(Saccharopolyspora),且Thermoactinomyces相对丰度在曲皮发酵过程中先上升后下降,在曲心发酵过程中则相反;主要优势真菌属有复膜孢酵母属(Saccharomycopsis)、嗜热真菌属(Thermomyces)和链格孢属(Alternaria),Saccharomycopsis相对丰度在曲皮发酵过程中上升速度快于曲心。

Medium-high temperature Daqu is an important source of microorganisms in the fermentation system of strong-flavor(Nongxiangxing)Baijiu.The difference and change rule of microbial community in Qupi(outer of daqu)and Quxin(interior of daqu)of medium-high temperature Daqu during fermentation process were analyzed by high-throughput sequencing technology combined with the determination of physicochemical indexes.The results showed that the moisture content,acidity and temperature of Quxin were higher than those of Qupi during fermentation process.Microbial diversity and richness index in Qupi were always higher than that in Quxin.The main dominant microbes in Qupi and Quxin were consistent,but the change rule of dominant microbes was quit different.Firmicutes,Actinobacteriota and Proteobacteria were the dominant bacterial phyla in Qupi and Quxin,and the relative abundance of Firmicutes in Qupi increased earlier than that in Quxin prior period of fermentation.Ascomycota,Basidiomycota and Mucoromycota were the dominant fungal phyla in Qupi and Quxin,and the relative abundance of Ascomycota in Quxin was slightly higher than that in Qupi during fermentation period.The main dominant bacterial genera in Qupi and Quxin were Thermoactinomyces,Lactobacillus and Saccharopolyspora.The relative abundance of Thermoactinomyces first increased and then decreased during Qupi fermentation,but it was opposite during Quxin fermentation period.The main dominant fungal genera were Saccharomycopsis,Thermomyces and Alternaria,and the relative abundance of Saccharomycopsis in Qupi increased faster than that in Quxin during fermentation period.