Effect of ionic strength on the inactivation of micro-organisms by microwave irradiation

Microwave irradiation at 2450 MHz inactivated the cells of Escherichia coli , Staphylococcus aureus and Candida albicans suspended in a phosphate buffe r. The rate of cell inactivation was proportional to that of the increase i n temperature accompanied by microwave irradiation. The inactivation rates of E. coli and C. albicans were affected by addition of NaCl and KCl, but n ot by sucrose. The maximal inactivation effect was exerted at concentration s of 0.5-1.0 mol l(-1), and the end-point temperature was the highest at th e same salt concentrations. Correlation of both the electroconductivity and di-electric loss of ionic solutions with the heating by microwave irradiat ion was discussed.