Environmental factor driven microbial interactions regulate flavor metabolisms in polymicrobial fermented alcoholic...

Fermented alcoholic beverages are globally cherished for their diverse sensory profiles, shaped by complex microbial metabolism. Environmentally-driven microbial interactions play a significant role in regulating the synthesis of flavor metabolites. However, mechanisms linking environmental factors to microbial interactions and flavor formation are unclear, hindering the optimization of fermented alcoholic beverages. This work systematically discussed regulatory mechanisms by which microbial interactions govern flavor formation in environment-driven polymicrobial fermentation processes of alcoholic beverages. By integrating representative global fermented alcoholic beverages (e.g., Baijiu, Pulque, and grape wine), we elucidated the framework of Environmental factors-Microbial interactions-Flavor regulation, a dynamic coupling framework. This framework indicated that environmental factors drove microbial interactions, which in turn regulated flavor metabolism. Concurrently, flavor metabolites provided feedback to reshape the microenvironment, thereby forming a closed framework. Key findings were concluded: (i) environmental gradients (e.g., in temperature, oxygen, pH) shaped microbial interaction by modulating thermodynamic, electrochemical, and kinetic equilibria; (ii) these interactions directly orchestrated flavor metabolome assembly, where synergy enhanced target esters (e.g., ethyl hexanoate), competition balanced diversity, and antagonism suppressed off-flavors; (iii) flavor metabolites, in turn, provided feedback by chemically and physically reshaping the microenvironment (e.g., via acidification and ethanol-driven anaerobiosis); and (iv) cross-scale methodologies (multi-omics, computational modeling, IoT sensing) enabled deciphering the framework from cellular to community levels. The framework establishes a foundation for designing synthetic microbial consortia, enhancing starter culture robustness for stable flavor production, and guiding targeted flavor optimization.