The dynamic changes of chemical components and microbiota during the natural fermentation process in Da-Jiang, a Chinese popular traditional fermented condiment

Abstract There is limited information on the chemical components and microbiota changes involved in da-jiang , a Chinese popular traditional fermented soybean condiment. Therefore, dynamic changes both in physicochemical quality and microbial community diversity of 20 samples of naturally fermented da-jiang collected over 95 days were measured, and we classified the samples into 5 groups (each containing 4 time points) according to the results. Based on OTUs analysis, Group 2 and Group 3 might represent the shift-stage between bacteria and fungi. Also, our results demonstrated that the formation of flavour, nutrient and quality of the traditional da-jiang were actually related to all of microbial community, especially the increased bacteria, including Staphylococcus and Leuconostoc . Correspondingly, ‘Membrane Transport’, ‘Carbohydrate Metabolism’, ‘Amino Acid Metabolism’ and ‘Replication and Repair’ were the top 4 KEGG pathways based on bacterial genes. The findings are expected to be helpful for us not only to understand the formation of flavour, taste and quality of traditional fermented da-jiang , but also to improve the industrialised fermented da-jiang .