Liquor fermentation industry reshapes soil microbiomes and drives CO₂ emissions via microbial dispersal

The rapid expansion of industrial fermentation has raised concerns about its environmental impacts, particularly regarding microbial dispersal from production facilities into adjacent terrestrial ecosystems; however, the ecological and functional consequences of microbial introductions originating from fermentation facilities remain poorly elucidated. We studied eight Chinese liquor fermentation facilities spanning 26°-47°N and 83°-124°E, covering the major geographical range of the industry. Using large-scale soil metagenomics, in situ CO₂ flux measurements, and microcosm experiments, we demonstrate that industrial fermentation significantly alters local soil microbial communities and enhances carbon decomposition potential. The results showed that soil carbon decomposition genes increased 13.6 % around fermentation facilities. Biologically, the fermentation process at the facilities introduced microorganisms into soil, such as Actinobacteria, whose abundance increased by 2.8 %. These microorganisms directly increased the abundance of carbon decomposition genes in the soil, while Actinobacteria also enhance soil carbon decomposition capacity by reducing microbial α diversity. Abiotically, the soil total carbon increased by 3-89 % around facilities, thereby enriching carbon decomposition genes. These soil microbial activities changed by fermentation facilities lead to an increase in soil CO₂ emissions. Our study provides the first evidence that industrial fermentation facilities inadvertently modify soil microbial community and function. These findings establish a critical link between fermented food production systems and terrestrial carbon emissions, with important implications for sustainable fermentation practices and climate-smart industrial planning.