Disintegration of Biomacromolecules by Dielectric Barrier Discharge Plasma in Helium at Atmospheric Pressure

The inactivation mechanism of microorganisms by plasma has been attracting much attention of researchers in recent years. Some different explanations have been postulated from physical, chemical, and biological views. In this paper, we investigate the inactivation mechanism of cells exposed to dielectric barrier discharge plasma in helium at atmospheric pressure from a biochemical view, i.e., disintegration of biomacromolecules, particularly the polysaccharide on cell wall and membrane-bound proteins. The experimental results showed that a series of complex chemical reactions happened in cell debris suspension and cell suspension, leading to a decrease in the concentration of membrane-bound proteins and an increase in the concentration of proteins released from cells. Cell debris could be effectively decomposed by plasma to amino acid, maltose, glucose, acetic acid, and so on. This might be the main reason for cell lysis and death.