Enhanced bacterial biosensor for fast and sensitive detection of oxidatively DNA damaging agents

A number of known and potential chemicals may cause substantial damage to genomic DNA, further inducing mutagenesis and carcinogenesis. To screen potentially genotoxic compounds from a multitude of chemicals, fast and senstive bioanalytical technologies are desirable. By taking advantage of the DNA damage-dependent SOS response (a regulatory signal initiated by damage to DNA or the physiological consequences of such damage in prokaryotes) in reactive oxygen species (ROS)-sensitive bacterium and the enhanced green fluorescent protein reporter, we constructed a composite bacterial biosensor for detection of DNA damage agents. The sensitivity of the bacterium to ROS induced DNA damage is 10-20-times enhanced by the knockout of one alkyl hydroperoxide reductase gene and two catalase genes. This biosensor can be used for fast and sensitive detection of DNA damaging agents among which some cannot be detected by previous bacterial biosensors, demonstrating the potential and promising applications for evaluation of DNA damage and for screening of DNA damaging agents in large scale.