Bactericidal effects of non-equilibrium cold plasma on Geobacillus stearothermophilis and Bacillus cerus

摘要

Low temperature air plasma at atmospheric pressure is a recently developed technology thatrncan be used to destroy bacteria. Plasma is a collection of charged particles and neutrals,rnincluding free radicals, that are chemically very active. In addition to the formation of freernradicals, UV radiation can also be produced. The combination of charged particles, freernradicals, and UV light can result in destruction of microorganisms. This paper presents a studyrnaimed to determine if cold air plasma, applied in a direct and indirect mode, inactivates the heatrnresistant microorganisms, Geobacillus stearothermophilus and Bacillus cereus vegetative cellsrnand spores. It is found that cold air plasma exposure significantly inactivated Geobacillusrnstearothermophilus vegetative cells and Bacillus cereus vegetative cells and spores; however,rnGeobacillus stearothermophilus spores were not significantly inactivated.