Background: Microbial fermentation is a foundational bioprocess that converts agricultural raw materials into stable, nutritious, and sensory-enhanced foods while supporting preservation, waste valorization, and circular resource flows. Traditional practices relying on spontaneous or mixed cultures of bacteria, yeasts, and fungi have sustained communities for millennia. Modern systems integrate controlled, solid-state, submerged, and precision fermentation to address rising food demand, nutritional insecurity, and environmental pressures.
Objective: This review synthesizes the microbial ecology, biochemical mechanisms, technological innovations, nutritional and safety outcomes, sustainability contributions, industrial applications, and remaining challenges of microbial fermentation across agriculture and food systems, with emphasis on emerging genomics, metabolomics, synthetic biology, artificial intelligence, and digital monitoring tools.
Methods: A structured literature review was performed using PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar. Search terms included microbial fermentation, food fermentation, agricultural waste valorization, precision fermentation, probiotics, and related combinations. Peer-reviewed studies, reviews, and industrial reports from 2019–2026 were prioritized, supplemented by landmark classical works. Inclusion required direct relevance to agricultural or food fermentation; exclusion applied to poorly documented or non-scientific sources. Literature was analyzed by microorganism, substrate, process type, biochemical transformation, nutritional/functional effects, safety, industrial maturity, and sustainability.
Results: Lactic acid bacteria, yeasts, filamentous fungi, acetic acid bacteria, Bacillus species, and mixed consortia drive carbohydrate fermentation, proteolysis, phytate degradation, vitamin synthesis, and bioactive metabolite formation. Controlled and precision fermentation improve reproducibility, while solid-state systems enable efficient agro-waste conversion into enzymes, organic acids, and functional ingredients. Omics and AI-supported digital twins enhance process prediction and optimization. Nutritional gains include higher protein digestibility, mineral bioavailability, and bioactive peptides; safety depends on hygiene, starter authentication, and control of biogenic amines and mycotoxins. Sustainability benefits arise from waste valorization and resource efficiency but are contingent on full life-cycle performance.
Conclusion: Microbial fermentation remains central to resilient, nutritious, and circular food systems. Integration of traditional knowledge with precision tools, synthetic biology, multi-omics, and AI-enabled smart platforms offers the most promising route to scalable, safe, and sustainable next-generation fermentation systems, provided regulatory, economic, and consumer-acceptance barriers are addressed through interdisciplinary collaboration and industrial validation.