Physicochemical Characteristics and Fungal Community Structure of Different Colored Jiang-Flavor Daqu

The fungal community diversity and structure in different colored Jiang-flavor Daqu (yellow, black and white) were investigated by high-throughput sequencing, and the reason for the physicochemical differences between the three Daqu was analyzed. The results showed that the liquefying power of yellow Daqu (YQ) was higher than that of black Daqu (BQ) and white Daqu (WQ), and the fermenting and esterifying power of YQ (1.56 and 22.63 U, respectively) and BQ (1.51 and 22.48 U, respectively) were higher that those of WQ. The dominant fungi in YQ and BQ were Aspergillus, Cladosporium and Phylctinia, while those in WQ were Aspergillus, Thermoascus, and Byssochlamys. In addition, the fungal community structure and species abundance in YQ were similar to those in BQ. Nonetheless, WQ had a great difference in fungal community structure at the genus level from, and low similarity of species to YQ and BQ. Linear discriminant effect size (LEFse) analysis showed that the fungal community structure of different colored Jiang-flavor Daqu differed in terms of Saccharomyces, Thermoascus, Byssochlamys and several other genera with low abundance. The results of this study lay the foundation for the application of functional fungi in Jiang-flavor Daqu, and provide theoretical support for improving the fermentation performance of Jiang-flavor Daqu.