A comparison of microbial communities and volatile compounds in wheat Qu from different geographic locations

Wheat Qu contains various microorganisms and is the fermentation starter for rice wine. The impact of geographic location on the volatile compounds and microbial communities in wheat Qu remains unknown. This study demonstrated significant differences in the volatile compound profiles of wheat Qu from different regions of China. Phenylethyl alcohol, hexadecanoic acid methyl ester, 9-octadecenoic acid methyl ester, and 2-octanone were the main volatile compounds detected. The bacterial and fungal communities in wheat Qu also differed significantly according to geographic location with both communities explaining the variation in volatile compounds (bacteria making the greater contribution). The bacterial community was dominated by Pediococcus, Weissella, and Lactobacillus while the fungal community was dominated by Saccharomycopsis and Rhizopus. Bacteria exhibited more significant associations with volatile compounds than fungi did. Prediction of metabolic function demonstrated significantly different profiles for the bacterial communities from different regions. These data showed that geographic location considerably affects the composition of volatile compounds and microbial communities in wheat Qu, with the bacterial community being the main contributor to variation of volatile compounds.