Abstract
Daqu, as an essential saccharifying and fermentative agent during Chinese liquor manufacture, is closely related to the quality and yield of liquor. In order to explore the microbial community structure during the process of Daqu production, the phospholipid fatty acid (PLFA) patterns were analyzed. The results obtained by measuring the PLFA contents of pure mycelium and raw materials demonstrated that PLFA analysis was appropriate to explore the characteristics and shifts of the microbial community in Daqu sample. Analysis of the microbial community of Daqu by PLFA method suggested that fungi predominated the total amounts of biomass in Daqu. In addition, changes in contents of fungi and bacteria were also investigated during Daqu-making. From the shaped stage to the finished stage of Daqu, fungi dominated gradually, and a small amount of bacterial biomass were detected in all finished Daqu samples. In three finished Daqu samples, the fungal biomass accounted for 68.85% - 80.11% of total biomass. Furthermore, the contents of gram-positive bacteria were higher than that of gram-negative bacteria in all Daqu samples.
