Linking Microbial Functional Gene Abundance and Daqu Extracellular Enzyme Activity: Implications for Carbon Metabolism during Fermentation

• Published in: Foods Vol. 11; no. 22; p. 3623
• Main Authors: Zhang, Yu-Ting, Deng, Yu-Ke, Zou, Yong-Fang, Han, Bao-Lin, Pu, Ji-Zhou, Rao, Jia-Quan, Huang, Dan, Luo, Hui-Bo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.11.2022; MDPI
• Subjects: Annotations; Carbohydrate metabolism; Carbohydrates; Carbon; Cellulose; Daqu; Data processing; Enzymatic activity; Enzyme activity; Enzymes; Ethanol; extracellular enzymes; Fermentation; Food science; Functionals; Genes; Genetic testing; Lignin; Liquefaction; Metabolism; Metabolites; Metagenomics; Microorganisms; Network analysis; Phenols; Prokaryotes; Pyruvic acid; Software; Sugar; United States > US; China; carbohydrates; Daqu; extracellular enzymes; metagenomics
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods11223623

is the starter of , it provides the microbes and enzymes necessary for fermentation. Studies have already established carbohydrate metabolism as the primary functional module in fermentation. The present study investigated the changes in microbial functions and the relationship between carbohydrate metabolism-related functional genes and extracellular enzyme activity during the fermentation. Amplicon sequencing identified 38 bacterial and 10 fungal phyla in samples, while shotgun metagenomic sequencing classified and annotated 40.66% of the individual features, of which 40.48% were prokaryotes. KEGG annotation showed that the pathways related to metabolites were less in the early fermentation stage, but higher in the middle and late stages. The functional genes related to pyruvate metabolism, glyoxylate and dicarboxylate metabolism, and propanoate metabolism were relatively high in the early and late stages of fermentation, while that for start and cross metabolism was relatively low. The study also found that amino sugar and nucleoside sugar metabolism were dominant in the middle stage of fermentation. Finally, the correlation network analysis showed that amylase activity positively correlated with many carbon metabolism-related pathways, while liquefaction activity negatively correlated with these pathways. In conclusion, the present study provides a theoretical basis for improving and stabilizing the quality of