Quorum quenching driven enzymatic activity and metabolic pathway modulation in anaerobic reactor for enhanced methane...

The effect of bioaugmentation with the quorum-quenching bacterium Proteus sp. ZJ5 on methane production during anaerobic process was evaluated at dosages of 0-280 mg·L^-1. The maximum methane yield was achieved at 140 mg·L^-1Proteus sp. ZJ5, showing a 17 % increase over the control. Enhanced methane production correlated with elevated activities of key enzymes, including protease, α-glucosidase, acetate kinase, and electron transport system, particularly α-glucosidase, which increased by 178 %. The modified Gompertz model confirmed greater methane potential, shorter lag time, and improved COD removal. Metagenomic analysis revealed notable shifts in microbial community structure, characterized by increased relative abundances of hydrogenotrophic methanogens such as Methanosarcina and Methanoculleus, as well as enrichment of genes involved in glycolysis, amino acid metabolism, and methanogenesis pathways. These results demonstrate that Proteus sp. ZJ5 enhances methane recovery by modulating enzymatic activity and microbial metabolic pathways, providing new insight into improving anaerobic treatment performance.