Degradation Characteristics of Acylated Homoserine Lactones in Activated Sludge

摘要

A mechanism of microbial cell-cell signaling, known as quorum sensing (QS), has been reported to influence the performance of wastewater treatment process. The concentration of signaling molecules of QS is determined by the balance between production and degradation but there are few studies on the characteristics of degradation in activated sludge, which would affect the detectability and quantification of signaling molecules. In this study, we aimed to investigate the degradation characteristics of acylated homoserine lactones (AHLs) in activated sludge and develop a method to suppress the degradation during analytical treatments. Spike and recovery tests revealed that the most of added AHLs were quickly degraded within 12 min in activated sludge. We also explored and were able to detect possible degradation products of AHLs using a high resolution mass spectrometer. The type of detected degradation products varied among different AHLs, indicating different degradation mechanisms. When HC1 was added (pH 2-3), the degradation was slowed, being an effective method to suppress AHL degradation during analytical procedures.