Synergistic Ecffect of Microwave Heating and Hydrogen Peroxide on Inactivatio of Microorganisms

Abstract

Escherichia coil K-12 isogenous strains and Pseudomonas ae ruginosa 102 were used to study the synergistic effects of combined microwave heating at short-time processing with low concentrations of hydrogen peroxide. The effect of tnicrowave heating to temperatures of 40,50 and 60 °C, as well as the concentration ofhydro gen peroxide (0.05,0.08 and 0. 1%), the sequence of the agents’ use, the nature of microorganisms on the survival of cells, DNA damages and interaction factors were studied. A method of anomalous viscosity time dependencies (AVTD) was used for measurement of the changes of genome conformational state (GCS) simultaneously with bacterial survival determination. The synergistic effect of microwave heating and low concentrations of hydrogen peroxide was observed under combined application, and reached a maximum when the cells were exposed to microwave heating to 50 °C and 0.08% hydrogen peroxide simultaneously. Both maxima of cell destruction and DNA injuries have been achieved by successive exposure to (MW + 10 min 112O2) to 60 °C and 0.08% hydrogen peroxide. The mechanisms of synergistic effects, the role of a disturbance of DNA repair and the interaction of sublethal injuries caused by different agents are discussed.