Development of an extraction method and LC-MS analysis for N-acylated-l-homoserine lactones (AHLs) in wastewater treatment biofilms

Abstract

N-Acylated-l-homoserine lactones (AHLs) play a vital role in Gram-negative bacteria communication by promoting the formation of extracellular polymeric substances (EPS) and biofilms. However, the low concentration of these AHL signals makes the process difficult to understand. A robust and sensitive pretreatment method for AHL detection was developed in this work. Compared with eight different solid-phase extraction (SPE) columns and three various solid extraction method, we found that the UE (ultrasonic extraction) and an Oasis hydrophilic-lipophilic-balanced (HLB) sorbent in column format combined with ultra-performance liquid chromatography linked to tandem mass spectrometry (UPLC-MS/MS) can be successfully used for systematic pretreating moving bed biofilm reactor (MBBR) biological samples to extract AHLs and determine concentration of AHLs in wastewater treatment biofilms. This easy-to-follow protocol makes it ideal for quantitative analyses of AHLs in wastewater treatment biofilms.

Keywords: N-Acylated-l-homoserine lactones (AHLs); Quorum sensing (QS); Solid phase extraction (SPE); Ultrasonic extraction (UE).