Unraveling the impact of geographic distance on the microbial communities of jiuyao samples in the Yangtze River Basin: From upstream to downstream

Jiuyao, an essential binomial fermenting agent in the huangjiu brewing process, is closely related to the flavor and quality of huangjiu. Meanwhile, microbial terroir is essential to the formation of regional characteristics of jiuyao. In this paper, 22 types of jiuyao samples were collected from the upstream (US), midstream (MS), and downstream (DS) regions of the Yangtze River, where its production is predominantly located. The analysis of the microbial communities in these samples aimed to uncover distribution patterns associated with geographic locations. The predominant microbial taxa identified across all regions included Bacillus subtilis , Pediococcus pentosaceus, Rhizopus oryzae, Saccharomycopsis fibuligera , and Saccharomyces cerevisiae . PCoA and NMDS analysis showed significant differences ( P < 0.01) in the bacterial and fungal compositions among the three regions. A total of 23 specific bacterial biomarkers and 24 specific fungal biomarkers were detected in the three groups by LEfSe analysis. Additionally, distance decay curves demonstrated that microbial community similarity decreased with increasing geographic distance. pH, amino nitrogen, reducing sugar, mean annual precipitation and relative humidity were found to have a significant effect on the composition of microbial communities in different jiuyao samples (P < 0.05). Correlation analysis identified a significant positive association between glucoamylase activity and certain microbes, including Pseudomonas fluorescens , Wickerhamomyces anomalus , Clavispora lusitaniae , and Geotrichum silvicola (P < 0.05). This research lays a theoretical foundation for regional optimization of jiuyao production by elucidating the microbial communities and their variations across the Yangtze River Basin. • Unraveling the geographic variation in microbial communities of jiuyao samples. • Microbial modularity and shared taxa vary by region, indicating ecological influences on community assembly. • Moisture content, pH and amino nitrogen correlated the microbiota structure. • Dominant taxa in jiuyao such as Rhizopus oryzae , and Saccharomycopsis fibuligera drive key enzymatic activities.