Convenient and sensitive evaluation of a superoxide anion-generating reagent methyl viologen by Escherichia coli harboring a soxS'::gfp reporter plasmid

We constructed a reporter system to detect a superoxide-generating methyl viologen using SoxRS of Escherichia coli and GFP of Aequorea victoria. E. coli carrying this plasmid exhibited strong fluorescence when grown in the presence of a superoxide-generating reagent methyl viologen. The fluorescence intensity observed in the stationary phase culture of the transformant increased in response to the methyl viologen concentration in a range of 0.01 MicroM to 10 MicroM.