A novel system for efficient gene expression and monitoring of bacteria inaquatic environments

In a previous study, we reported the identification of Escherichia coli gen es with increased expression in an aquatic environment. Here, we describe t he use of one of these genes, gapC, as an expression system in freshwater h abitats. We have identified the transcriptional start site of gapC and anal ysed the synthesis of the GapC protein during incubation in aquatic medium. The promoter of gapC was used to construct fusions to the reporter genes I acZ and gfp, Analysis of these fusions indicates the potential of gapC as a valuable tool for the detection of E. coli in freshwater habitats, as well as for expressing other genes in aquatic environments.