Radiation biology. Radioecology
ISSN: 0869-8031

Archives → 2022 → Vol. 62, № 3 → pp. 240-249

Article

Genotoxic Effect of Paraquat Radiomimetic on Escherichia coli Bacteria

Machigov E.A.¹, Igonina E.V.¹, Sviridova D.V.¹, Rubanovich A.V.¹, Abilev S.K.^{1, 2}

¹Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia ²Lomonosov Moscow State University, Moscow, Russia

Abstract

Paraquat at a concentration of 0.01 mol/L caused the most intense luminescence of E. coli pSoxS-lux and E. coli pKatG-lux biosensors, which indicates the formation of superoxide anion radical (О^2–) and hydrogen peroxide (Н₂О₂) in bacterial cells, respectively. At a paraquat concentration of 0.1 mol/L, a decrease in the intensity of luminescence of biosensors was observed, which was associated with a decrease in the survival of bacteria from 4 × 10⁷ in the control to 1x10⁵ in the experiment of colony-forming units (CFU). As a result of recalculating the luminescence intensity index per 1000 CFU, a sharp increase in the expression of the superoxide dismutase gene from 0.13 in the control to 4.36 and 119 conventional units at paraquat concentrations of 0.01 mol/L and 0.1 mol/L, respectively, was shown. The antioxidants glutathione and N-acetylcysteine reduced the concentration of free radicals generated by paraquat in cells and increased bacterial survival. The method of gel electrophoresis revealed the DNA-damaging ability of paraquat, the severity of which depends on both its concentration and the concentration of antioxidants.

Keywords

Paraquat, superoxide radical anion, hydrogen peroxide, biosensors, antioxidants, bacterial survival, dna fragmentation, electrophoresis