gfp -Based N -Acyl Homoserine-Lactone Sensor Systems for Detection of Bacterial Communication

Abstract

ABSTRACT In order to perform single-cell analysis and online studies of N -acyl homoserine lactone (AHL)-mediated communication among bacteria, components of the Vibrio fischeri quorum sensor encoded by luxR-P luxI have been fused to modified versions of gfp mut3∗ genes encoding unstable green fluorescent proteins. 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 combination with epifluorescent microscopy, the sensitivity of the sensor enabled AHL detection at the single-cell level and allowed for real-time measurements of fluctuations in AHL concentrations. This green fluorescent AHL sensor provides a state-of-the-art tool for studies of communication between the individuals present in mixed bacterial communities.