Bidirectional regulation strategies of food microorganisms based on mechanistic insights into temperature, osmotic, and acid stresses.

Food microorganisms act as a double-edged sword in production and storage. Beneficial microbes create distinctive flavor, texture, and nutritional value, whereas harmful microbes threaten food safety and shelf life. Their survival and adaptation to abiotic stresses-temperature fluctuations, pH shifts, and osmotic challenges-directly influence quality control and safety management. This review systematically summarizes the physiological and molecular mechanisms by which food microorganisms adapt to heat, cold, acid, and osmotic stresses, including membrane lipid remodeling, exopolysaccharide synthesis, compatible solute accumulation, and stress protein expression. On this basis, a "bidirectional regulation" strategy is proposed, in which beneficial strains are strengthened to improve fermentation efficiency and flavor stability, whereas vulnerabilities of harmful microbes are targeted to minimize contamination risks. Advances in multi-omics and systems biology are highlighted to uncover the underlying regulatory networks, while strategies for enhancing the robustness of beneficial microbes and suppressing the persistence of harmful ones are discussed, covering physical, chemical, and biological interventions used in food processing and preservation. The integration of omics-driven insights, artificial intelligence, and synthetic biology offers promising avenues for future breakthroughs. Overall, this review provides a systematic framework and feasible technological pathways for the directed management of food microorganisms, thereby supporting the synergistic optimization of food safety and quality.