Hydrogen peroxide is widely used as a disinfectant by generating oxidative stress. The chelate of ethylenediaminetetraacetic acid (EDTA) and ferrous iron (EDTA-Fe) was used to increase oxidative stress and bactericidal effects. The Escherichia coli (E. coli) was added to a beef extract culture medium and treated with various doses of test reagents, including hydrogen peroxide, EDTA-Fe chelate, and antioxidants (vitamin C and vitamin E) . All reagents were scanned individually or in combination to trace potential interference in optical density (OD) measurements and eliminate reagent-related interference. Medium supplemented with 13.79 mM hydrogen peroxide resulted in a large increase in the mortality of E. coli, and the highest disinfection efficiency for EDTA-Fe was observed at a neutral pH. The death of the cell of E. coli was significantly inhibited by the presence of catalase, but not vitamins C and E, suggesting that hydroxyl radicals were not generated during the EDTA-Fe-hydrogen peroxide reaction.
Keywords: Antioxidants; Hydrogen peroxide; Iron; Iron chelating agents; Oxidative stress.