Generation of novel bacterial regulatory proteins that detect priority pollutant phenols

The genetic systems of bacteria that have the ability to use organic pollut ants as carbon and energy sources can be adapted to create bacterial biosen sors for the detection of industrial pollution. The creation of bacterial b iosensors is hampered by a lack of information about the genetic systems th at control production of bacterial enzymes that metabolize pollutants. We h ave attempted to overcome this problem through modification of DmpR, a regu latory protein for the phenol degradation pathway of Pseudomonas sp. strain CF600. The phenol detection capacity of DmpR was altered by using mutageni c PCR targeted to the DmpR sensor domain. DmpR mutants were identified that both increased sensitivity to the phenolic effecters of wild-type DmpR and increased the range of molecules detected. The phenol detection characteri stics of seven DmpR mutants were demonstrated through their ability to acti vate transcription of a lacZ reporter gene. Effecters of the DmpR derivativ es included phenol, 2-chlorophenol, 2, 1-dichlorophenol, 4-chloro-3-methylp henol, 2,4-dimethylphenol, 2-nitrophenol, and 4-nitrophenol.