Endogenous quorum sensing orchestrates microbial social behaviors for anaerobic digestion adaptation to temperature reduction

Quorum sensing molecules, especially AHLs and AI-2, played a crucial role in regulating microbial social behaviors and EPS production under temperature stress. Moreover, These QS changes coincide with a shift from acetoclastic to hydrogenotrophic methanogenesis and with EPS composition adjustments (PN/PS changes), suggesting that QS promotes low-temperature adaptation by regulating EPS secretion and community adhesion, thereby stabilizing granule structure and maintaining metabolic syntrophy and methanogenesis. These findings enhance our understanding of temperature effects on anaerobic systems and provide a basis for optimizing psychrophilic anaerobic processes, addressing the need for energy-efficient wastewater treatment in colder climates.