Cutting Off Communication

Abstract

Biotechnology![Figure][1] CREDIT: N. KEVITIYAGALA/ SCIENCE Many bacteria communicate with one another through the secretion and uptake of small signaling molecules. If this process, known as quorum sensing, is disrupted, bacterial communities can no longer collectively respond to environmental stresses or cooperatively build complex structures such as biofilms. Yeon et al. have leveraged such a disruption to prevent biofouling—the clogging of membrane pores by accumulated particulate matter and bacteria—in wastewater treatment apparatus. The addition of a deactivating enzyme (acylase) quenched the quorum-sensing signal required for bacteria to form biofilms and thus increased the long-term performance of the filtration membrane. Furthermore, the use of a cell-sized magnetic carrier stabilized the acylase and facilitated its recovery and reuse over multiple operation cycles. Fortunately, the quenching process did not interfere with other beneficial bacterially driven processes in the bioreactor, such as the degradation of solid-phase organic matter. Although acylase is only specific to one type of signaling molecule, this procedure could eventually incorporate additional enzymes to quench the few other known quorum-sensing signals, effectively blocking all bacterial communication channels. Environ. Sci. Technol. 43 , 10.1021/es901323k (2009). [1]: pending:yes