Microbial biogeography of pit mud from an artificial brewing ecosystem on a large time scale: all roads lead to Rome

Abstract

ABSTRACT The fermentation process of strong-flavor Baijiu occurs in an underground cellar surrounded by mud, where grains are decomposed and generate new flavor substances. Pit mud microbiome plays a pivotal role in the formation of Baijiu flavor, which is positively correlated with cellar age. Previous research on the pit mud microbiome was often conducted for a specific distillery, making it hard to draw a general conclusion to decipher the pit mud microecosystem in such a unique brewing environment. Hence, in this study, we attempt to unravel community formation mechanisms through research in pit mud microbial biogeography based on 12 independent bacterial studies comprising qualified data sets of 302 samples clearly marked with cellar age from five major producing provinces. We found c