Analysis of fungal community diversity and quality properties of medium-temperature Daqu from different wheat varieties

The main quality indexes of 5 varieties of wheat were determined by national standard methods, and the diversity of fungal community in medium-temperature Daqu from 5 wheat varieties was studied using high-throughput sequencing technology. Meanwhile, the sensory quality and physicochemical properties of Daqu were detected and compared, and the correlation between the main quality indexes of wheat, physicochemical properties of Daqu and dominant fungal genera was further explored. The results showed that medium-temperature Daqu made from medium-gluten wheat had a higher comprehensive sensory score, the preferable physicochemical properties and the highest relative abundance of fungal community. A total of 3 dominant fungal phyla and 12 dominant fungal genera were annotated, and the dominant fungal genera shared by the medium-temperature Daqu from 5 wheat varieties were Thermomyces, Aspergillus, Issatchenkia, Cutaneotrichosporon and Candida. Daqu from medium-gluten wheat had 4 shared dominant fungal genera with similar relative abundance, while Daqu from strong-gluten wheat with the high powder rate had the lowest relative abundance of Aspergillus.8 dominant fungal genera were correlated with physicochemical properties of Daqu. Meanwhile, the crude protein and wet gluten contents of wheat were significantly positively correlated with Cladosporium (P<0.05), and significantly negatively correlated with Apiotrichum, Wallemia, unclassified_f_Microascaceae and unclassified_p_Ascomycota (P<0.05), while the correlation between starch content and the dominant fungi was the opposite of the above, and the powder rate also had effect on some fungal genera.