Effects of Polygonatum sibiricum on Microbial Community Structure and Functional Genes of Wheat Qu

Objective: To investigate the effect of the addition of 2.5% and 5% mass fractions of Polygonatum sibiricum on the microbial community structure and functional genes of wheat Qu, and on this basis to provide theoretical reference for future selection of Polygonatum sibiricum wheat Qu. Methods: The microbial composition and functional genes in Polygonatum sibiricum wheat Qu were annotated by macrogenomics techniques, and the effects of Polygonatum sibiricum on the microbial community structure and functional genes of wheat Qu were analyzed using principal component analysis, stacked histogram and cluster heat map. Results: The species richness and homogeneity of wheat Qu (HJ100) made by adding 2.5% mass fraction of Polygonatum sibiricum were higher than that of wheat Qu (HJ200) with 5% mass fraction and without the addition（PTMQ）. All there were differed at the genus and species levels. The dominant genera of HJ100 were Aspergillus, Paecilomyces, Rasamsonia, Limosilactobacillus, Rhizopus, Klebsiella, Pantoea and Puccinia, and the dominant genera of both HJ200 and PTMQ were Aspergillus, Paecilomyces and Rasamsonia. The dominant species of HJ100 were Paecilomyces varioti, Rasamsonia emersonii, Limosilactobacillus pontis, Pantoea agglomerans, Rhizopus microspores and Puccinia striiformis, and the dominant species of HJ200 and PTMQ were Paecilomyces varioti and Rasamsonia emersonii. Compared to HJ200 and PTMQ, the relative abundance of functional genes annotated by HJ100 showed higher homogeneity, there were a higher abundance of functional genes related to carbohydrate metabolism, protein and amino acid metabolism, which were directly associated with the quality of Huang Jiu. The brewing experiments showed that the Huang Jiu brewed by HJ100 was better than HJ200 and PTMQ in terms of total sugar and polysaccharide content, which could guarantee the functionality and quality of Huang Jiu, and HJ100 had a same fermentation capacity as PTMQ and HJ200. Conclusion: The addition of 2.5% mass fraction of Polygonatum sibiricum could improve the species richness and uniformity and quality of wheat Qu, and could be used for brewing Hung Jiu in the future.