Quorum quenching driven microbial community to biofouling control in membrane bioreactor for landfill leachate treatment

Membrane bioreactor (MBR) has been widely applied in landfill leachate treatment, with significant efforts focusing on sustainable and non-toxic strategies for biofouling mitigation. This study investigated the potential of the quorum quenching (QQ) bacterium Brucella sp. ZJ1 to control biofouling in a MBR system treating landfill leachate. Results demonstrate that QQ-MBR extended the time to reach a transmembrane pressure of 35 kPa by 3 similar to 10-fold compared with the control. After being operated in MBR for 40 days, QQ beads retained about 40 % of their quorum sensing (QS) signals degradation activity. Biofouling reduction was driven by surface scouring, alongside a notable QQ effect, evidenced by 27-41 % lower extracellular polymeric substance (EPS) concentrations and 60 % lower QS signal levels. Metagenomic analysis revealed that QQ beads significantly reduced QS-related and EPS production genes while increasing QQ-related genes in the membrane biocake, effectively mitigating biofouling. This study highlighted the role of QQ in reshaping the microbial community to sustainably reduce biofouling in landfill leachate MBR treatment.