不同贮存期高温大曲微生物群落演替与理化指标相关性分析

Correlation analysis of microbial community succession and physicochemical properties of Daqu in different storage periods

以不同贮存期的白酒高温大曲为研究对象,对其不同部位的微生物种群数量及其理化指标进行分析。结果表明,高温大曲经过120 d贮存后曲皮和曲心中的微生物总数均有显著增加,微生物群落结构亦有明显变化。贮存30 d时,曲皮中优势微生物为芽孢杆菌属(Bacillus)、不动杆菌属(Acinetobacter)、嗜热子囊菌属(Thermoascus)、嗜热真菌属(Thermomyces),曲心中优势微生物为高温放线菌属(Thermoactinomyces)、芽孢杆菌属(Bacillus)、嗜热子囊菌属(Thermoascus);贮存120 d时,芽孢杆菌属(Bacillus)、根毛霉属(Rhizomucor)在曲皮和曲心中均占优势。随着贮存时间进行,大曲还原糖含量逐渐增加,水分逐渐降低。大曲中不同部位微生物的变化与其理化性质存在对应关系。微小根毛霉(Rhizomucor pusillus)的变化与大曲中还原糖呈正相关,与水分呈负相关。芽孢杆菌属(Bacillus)、高温放线菌属(Thermoactinomyces)和嗜热子囊菌属(Thermoascus)的变化与大曲中水分呈正相关。

The physicochemical indexes and microbial diversity of the high temperature Daqu sampled in different storage periods were analyzed.The results demonstrated that the microbial amount was increased during storage and the microbial community was also significantly changed.After storage for 30 d,the dominant microorganisms in Daqu surface were Bacillus,Acinetobacter,Thermoascus and Thermomyces,while the dominant microorganisms in the central part were Thermoactinomyces,Bacillus,and Thermoascus.As the storage time increased to 120 d,the dominant microorganisms were Bacillus,Rhizomucor in both Daqu surface and central.The content of reducing sugar gradually increased,while the moisture gradually decreased during the whole storage period.Canonical correlation analyses revealed that the change of microbial community is highly related to these physicochemical factors.The changes of Rhizomucor pusillus were positively correlated with reducing sugar and negatively correlated with water content.The changes of Bacillus,Thermoactinomyces and Thermoascus were positively correlated with water content in Daqu.