Biofouling control by biostimulation of quorum‐quenching bacteria in a membrane bioreactor for wastewater treatment. Issue 12 (8th July 2016) - Yu, Huarong
ABSTRACT: Bacterial quorum quenching (QQ) has been shown to be effective in controlling biofouling in membrane bioreactors (MBRs) for wastewater treatment. However, the encapsulation of a sufficient level of QQ bacteria is complicated and difficult. In plant research, gamma‐caprolactone (GCL), which is structurally similar to the quorum signal, N ‐acyl homoserine lactone (AHL), was successfully used to specifically stimulate AHL‐degrading bacteria (biostimulation) in hydroponic systems to control blackleg and soft rot diseases in potato. In this study, the feasibility of enriching QQ bacteria from activated sludge by GCL was examined, and the effect of biostimulation on biofouling control in MBR treating domestic wastewater was investigated. The results showed that after enrichment with GCL, activated sludge could effectively degrade AHLs, and a QQ gene ( qsdA ) was augmented. The proposed biostimulation QQ strategy, by introducing and continuously dosing GCL, could significantly increase QQ activity, decrease AHL, control the secretion of extracellular polymeric substances (EPS), and thus, effectively control biofouling in an MBR. This biostimulation QQ strategy provides a more convenient option for biofouling control in MBR applications. Biotechnol. Bioeng. 2016;113: 2624–2632. © 2016 Wiley Periodicals, Inc. Abstract : The biostimulation of activated sludge systems in membrane bioreactors (MBR) by gamma‐caprolactone (GCL) was examined in terms of quorum quenching (QQ) activity and ability to control biofouling. N‐acyl homoserine lactone (AHL) can be effectively degraded by the GCL consortia. The biostimulation strategy promoted QQ gene expression, decreased AHL, reduced extracellular polymeric substances secretion, and proved to be effective for controlling biofouling in an MBR.