Mechanism of killing of microorganisms by a one atmosphere uniform glow discharge plasma

Summary form only given. We have previously demonstrated the efficacy of a one atmosphere uniform glow discharge plasma (OAUGDP) in killing bacteria and spores in seconds to minutes. The OAUGDP operates in air and produces a uniform plasma without filamentary discharges at room temperature, which is advantageous for sterilization of heat sensitive materials. The OAUGDP operates in a frequency band determined by the ion trapping mechanism provided that, for air, the electric field is above 8.5 kV/cm. The OAUGDP efficiently generates plasma reactive oxygen species (ROS) including atomic oxygen and oxygen species radicals without the requirement of a vacuum system. Recent experiments using this OAUGDP technology have been applied to understanding the mechanism of killing of various microorganisms. Experiments using ultraviolet adsorption to measure macromolecular leakage from treated bacterial cells indicate rapid destruction of membranes. Results from electron microscopy studies show that bacteria with an outer membrane are more susceptible to fragmentation than those without an outer membrane, probably due to the sensitivity of liqids to ROS. Consistent with these findings are results that show the relative resistance of non-enveloped viruses to the plasm. Further results will be presented describing these mechanisms including attempts to characterize altered macromolecules.