Methodology article

Detection of N-acyl homoserine lactones using a traI-luxCDABE-based biosensor as a high-throughput screening tool

Steve P Bernier^1,2 , Anne L Beeston^1,3 and Pamela A Sokol¹

¹Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Canada

²Département de Microbiologie, Institut Pasteur, Paris, France

³Canadian Food Inspection Agency, Lethbridge, Canada

author email corresponding author email

BMC Biotechnology 2008, 8:59doi:10.1186/1472-6750-8-59

Published:	30 July 2008

Abstract

Background

Bacteria use N-acyl homoserine lactone (AHL) molecules to regulate the expression of genes in a density-dependent manner. Several biosensors have been developed and engineered to detect the presence of all types of AHLs.

Results

In this study, we describe the usefulness of a traI-luxCDABE-based biosensor to quickly detect AHLs from previously characterized mutants of Burkholderia cenocepacia and Pseudomonas aeruginosa in both liquid and soft-agar co-culture assays in a high-throughput manner. The technique uses a co-culture system where the strain producing the AHLs is grown simultaneously with the reporter strain. Use of this assay in liquid co-culture allows the measurement of AHL activity in real time over growth. We tested this assay with Burkholderia cenocepacia and Pseudomonas aeruginosa but it should be applicable to a broad range of gram negative species that produce AHLs.

Conclusion

The co-culture assays described enable the detection of AHL production in both P. aeruginosa and B. cenocepacia and should be applicable to AHL analysis in other bacterial species. The high-throughput adaptation of the liquid co-culture assay could facilitate the screening of large libraries for the identification of mutants or compounds that block the synthesis or activity of AHLs.