Critical assessment of synthetic microbial community strategies in vinegar brewing: from design paradigms to industrialization bottlenecks

Vinegar brewing traditionally relies on complex, spontaneously assembled microbiota, which often results in batch-to-batch inconsistency and uncontrollable flavor profiles due to environmental fluctuations. Synthetic microbial communities (SynComs) represent a paradigm shift toward standardized, efficient, and precise biomanufacturing. This review critically assesses the application of SynComs in vinegar fermentation, evaluating four primary construction methodologies: isolation culture, core microbiome excavation, automated design, and gene editing. We elucidate the underlying mechanisms by which SynComs modulate flavor, emphasizing metabolic cross-feeding, resource competition, and quorum sensing (QS)-mediated population regulation that govern the synthesis of key organic acids and volatile compounds, such as tetramethylpyrazine and various esters. Despite notable successes in laboratory settings, the industrial translation of SynComs remains severely restricted. We systematically identify critical bottlenecks, including ecological vulnerability driven by spatial heterogeneity in solid-state fermentation (SSF), uneven viability loss during inoculum formulation, and biophysical limitations hindering QS signal diffusion. To bridge this translational gap, we propose an integrated, multidisciplinary roadmap leveraging Computational Fluid Dynamics (CFD)-assisted microenvironmental simulation, advanced preservation formulations, and Digital Twin-enabled smart fermentation. This framework aims to transition SynComs from empirical laboratory designs to robust, industrial-scale applications, ultimately providing a blueprint for the intelligent and precise regulation of traditional fermented foods.