Physicochemical indexes and fungal community diversity of medium-high temperature Baobao Daqu and brick-shaped Daqu

In this study, the diversity of fungal flora of medium-high temperature brick-shaped Daqu and Baobao Daqu from Songhe region was deeply analyzed using high-throughput sequencing technology, and the basic physicochemical properties were detected, aiming to explore the correlation between their physicochemical indexes and fungal community. The results showed that there were 58 operational taxonomic units (OTU) belonging to 3 phyla, 8 classes, 10 orders, 20 families and 30 genera. The α-diversity index values of the two species were similar, the structure of the flora was similar, but the average relative abundance was different. The common dominant fungal genera (relative abundance>1%) were Issatchenkia, Rhizopus, Candida, Wickerhamomyces, Rhizomucor, Torulaspora, and Lichtheimia, Aspergillus and Alternaria were the unique dominant fungi in Baobao Daqu and brick-shaped Daqu, respectively. The moisture, starch content and saccharifying power of brick-shaped Daqu were higher, and the acidity, fermentation power and esterification power of Baobao Daqu were higher. Among them, there were significant differences in moisture, acidity, saccharifying power, fermentation power and esterification power (P<0.05). Correlation analysis results showed that the physiochemical characteristics of Daqu had different effects on fungal community, and the effect of saccharification and esterification power on fungal community structure was particularly significant.