Cyclic digene system as a control element of a bacterial biosensor

The Escherichia coli JC158(pCIA12/pGFK5) strain carrying a cyclic digene system with a negative feedback on the pCIA12 plasmid reacting to the DNA damage by changing the synthesis level of reporter genes—GFP and β-galactosidase—was tested. The acquired phenotype was inherited by the next generations after the removal of the genotoxic action when the concentration of the DNA-damaging compounds was above the threshold level. A potential has been shown for the application of bacterial biosensors to monitor the presence of genotoxicants in the environment and to test the consequences of short-term exposures to toxic compounds.