Strategies for enhancing bioluminescent bacterial sensor performance by promoter region manipulation.

Genetically engineered microbial reporter strains are based upon the fusion of an inducible sensing element upstream of a reporting element, so that the construct emits a dose-dependent signal when exposed to the inducing compound(s) or stress factor(s). In this communication we described several general approaches undertaken in order to enhance the sensing performance of such promoter::reporter fusions. Significant improvements in detection sensitivity, response kinetics and signal intensity were achieved by modification of the length of the promoter-containing DNA fragment, by random or site-directed mutagenesis and by promoter duplication. The general nature of these genetics manipulations makes them applicable to other types of promoter::reporter fusions.