强化曲贮存过程中群落与代谢组分的变化规律

以常规大曲(B)和强化大曲(F)为对象，应用多相检测技术研究其贮存过程中微生物群落和代谢组分的变化。结果表明，贮存过程中2类大曲的糖化力和B曲的发酵力增高，而B曲的酯化力和液化力降低。2类大曲其余的理化性质、挥发性组分含量和微生物群落的α-多样性指数增减交替变化，且F曲的挥发性含量增高，种类增多。B曲和F曲的最适贮存周期分别是60～90和90～120 d。F曲细菌群落的α-多样性指数高于B曲的，真菌的则相反。B曲的优势菌Weissella与Pichia、Rhizomucor负相关，F曲中优势菌Bacillus与多数真菌属正相关。大曲中的挥发性物质与Bacillus、Thermomyces、Thermoascus、Rhizomucor、Saccharopolyspora和Pichia密切相关。Bacillus licheniformis强化增强了碳水化合物代谢能力，从而使四甲基吡嗪和2,3-丁二醇合成含量增高。研究结果为系统科学地判定大曲最佳贮存期奠定了基础。

Changes of community and metabolic components during the storage of fortified Daqu

The changes of microbial community and metabolic components during the storage of traditional Daqu(B-Daqu)and fortified Daqu(F-Daqu)were revealed by polyphasic examination.The results indicated that the ability of saccharifying was increased,the contents of volatile component and the microbiota ofα-diversity index changed alternating in B-and F-Daqu.The fermenting ability of B-Daqu and the content and types of volatiles in F-Daqu was increased,while the liquefying power and esterifying ability of B-Daqu were decreased.The optimal storage time for B-Daqu and F-Daqu were 60-90 and 90-120 d,respectively.Theα-diversity indexes of bacteria in F-Daqu were higher than that of B-Daqu,without fungi.Weissella,as dominant bacteria in B-Daqu,was negative correlated with Pichia and Rhizomucor.Bacillus,as the dominant bacteria in F-Daqu,was positively correlated with most fungal genera.Volatile components were closely related with Bacillus,Thermomyces,Thermoascus,Rhizomucor,Saccharopolyspora and Pichia.Carbohydrate metabolism ability was stronger when inoculation of Bacillus licheniformis,and the content of tetramethyl pyrazine and 2,3-butanediol was increased.This study provides the foundation that can be used to for determine the optimal storage period of Daqu.