gfp-based N-acyl homoserine-lactone sensor systems for detection of bacterial communication

In order to perform single-cell analysis and online studies of N-acyl homos erine lactone (AHL)-mediated communication among bacteria, components of th e Vibrio fischeri quorum sensor encoded by luxR-P-luxI have been fused to m odified versions of gfpmut3* genes encoding unstable green fluorescent prot eins. Bacterial strains harboring this green fluorescent sensor detected a broad spectrum of AHL molecules and were capable of sensing the presence of 5 nM N-3-oxohexanoyl-L-homoserine lactone in the surroundings. In combinat ion with epifluorescent microscopy, the sensitivity of the sensor enabled A HL detection at the single-cell level and allowed for real-time measurement s of fluctuations in AHL concentrations. This green fluorescent AHL sensor provides a state-of-the art tool for studies of communication between the i ndividuals present in mixed bacterial communities.