Plasma sterilization of Geobacillus Stearothermophilus by O2:N2 RF inductively coupled plasma

The aim of this work is to identify the main process responsible for sterilization of Geobacillus Stearothermophilus spores in O-2:N-2 RF inductively coupled plasma. In order to meet this objective the sterilization efficiencies of discharges in mixtures differing in the initial O-2/N-2 ratios are compared with plasma properties and with scanning electron microscopy images of treated spores. According to the obtained results it can be concluded that under our experimental conditions the time needed to reach complete sterilization is more related to O atom density than UV radiation intensity, i.e. complete sterilization is not related only to DNA damage as in UV sterilization but more likely to the etching of the spore.