Effects of non-equilibrium plasmas on microorganisms

Summary form only given. Non-equilibrium plasmas have been shown to be excellent sterilization agents. Garate and Alexeff (1998) used a corona discharge, and Laroussi and Sayler (1999) used an RF driven glow discharge. Also, most recently Alexeff and Laroussi have been able to generate a glow discharge at atmospheric pressure using a DC power source. The use of RF and DC driven discharges showed that a large population (/spl sim/10/sup 8/ per ml) of harmful microorganisms can be neutralized after a few minutes exposure to the plasma. The optimum exposure time is dependent on: the type of microorganism; the medium supporting the microorganism; the plasma power density, and the gas mixture used in the discharge. However, the biophysical and biochemical effects leading to the death of the cells of the microorganisms are yet to be understood. In this paper, we discuss the various factors which play an active role in the cell-plasma interaction.