Abstract:

In the present study, sterilization effects of high voltage electric field (HVEF) on E. coli in aqueous solution and under dry condition were studied, respectively. The results indicated that the sterilization effects under dry condition are more conspicuous than those in aqueous solution. Under dry condition the sterilization rate of E. coli is remarkably ascended with the increment of time and HVEF intensity. When treated for 1 min, the survival rate of E. coli under voltage at 1 kV/cm is 6 times of the control, that under voltage at 2 kV/cm is about half of the control, and then following with the increase of voltage, the survival rate is fluctuated around 20% of the control. When treated for 10 min, the survival rate of E. coli under voltage at 1 kV/cm is 49% of the control, and that under voltage over 3 kV/cm is less than 3% of the control. In aqueous solution, the variety tendency of survival rate of E. coli presents oscillatory type, and the effects are not satisfying. Altogether, the sterilization effects of HVEF under dry condition are significant, and may be applied in the disinfection and sterilization of dry materials.

Key words: high voltage electric field (HVEF), Escherichia coli, survival rate