Bacterial quorum sensing enhances biogas production from complex organic substrate

Accelerating food waste conversion to renewable biogas through anaerobic digestion is crucial for sustainable energy and waste management. Hydrolysis, the initial bottleneck step, relies on microbial enzymatic activity. Our research explored the potential of microbial quorum sensing (QS) to enhance this process, a mechanism controlling extracellular enzyme production. No native QS signals were observed in food waste slurries but quorum quenching activity was widespread, suggesting an inhibitory environment for QS. A substrate pretreatment regime that fostered the proliferation of QS-capable Proteobacteria was developed. Bioaugmentation with a Pseudomonas aeruginosa strain isolated from food waste, combined with pretreatment, reduced anaerobic digestion time by 20 % and increased biogas yield. Treating P. aeruginosa with QS signal molecules increased cellulase and lipase production, providing insight into the underlying mechanism by which anaerobic digestion was enhanced. This targeted bioaugmentation approach re-engineers the microbiome, promoting QS-mediated enhancements that improve biogas production efficiency and kinetics. • Food waste lacks quorum sensing but has quorum quenching capabilities. • Pretreatment, aeration and pH buffering reduce quorum quenching potency. • Pretreating food waste with QS viable Proteobacteria enhances its digestibility.