The Genotoxic Effect of the Paraquat Radiomimetic on Escherichia coli Bacteria

Paraquat at a concentration of 0.01 mol/L induces intense luminescence of E. coli pSoxS-lux and E. coli pKatG-lux biosensors, which indicates the formation of the superoxide radical anion (O2-) and hydrogen peroxide (H2O2), respectively, in bacterial cells. At a paraquat concentration of 0.1 mol/L, the luminescence intensity of biosensors decreases, as does bacteria viability from 4 x 10(7) colony-forming units (CFU) in the control to 1 x 10(5) CFU in the experiment. When recalculating the luminescence intensity index per 1000 CFU, the expression of the superoxide dismutase gene increases sharply from 0.13 in the control to 4.36 and 119 conventional units at paraquat concentrations of 0.01 and 0.1 mol/L, respectively. The antioxidants (glutathione and N-acetylcysteine) reduce the concentration of free radicals generated by paraquat in cells and increase the bacterial viability. The method of gel electrophoresis reveals the DNA-damaging ability of paraquat at a concentration of 0.1 mol/L, reduced by antioxidants.

Automated summary

The study investigates the effect of Paraquat on E. coli using biosensors. It is found that Paraquat generates superoxide radical anion and hydrogen peroxide, leading to decreased bacterial viability and luminescence intensity. Antioxidants are able to reduce the concentration of free radicals generated by Paraquat and increase bacterial viability.