Sterilizing Ability of High-Voltage Pulsed Discharge Plasma with Cavitation for Microorganisms Including Radio-Resistant Bacterium in Water.

There are various purification methods have been developed and applied to industrial wastewater with contaminated microorganisms. We previously reported that high-voltage pulsed discharge plasma with cavitation effectively kills Escherichia coli cells. We attempted to expand the application of this disinfection method by using microorganisms such as Bacillus subtilis, Deinococcus radiodurans, and Schizosaccharomyces pombe. These microbial cells were treated with the discharge plasma, and the cell viability, DNA damage, and morphological changes were analyzed to evaluate the bactericidal effect. Interestingly, D. radiodurans, a radio-resistant bacterium showed relatively high sensitivity to the discharge plasma. On the other hand, B. subtilis and S. pombe showed the resistance, showing both sporogenesis. The amount of DNA damage in the treated cells corresponded to the cell viability, but most of the treated cells did not show any morphological changes.