Degradation of bacteria by weakly ionized highly dissociated radio-frequency oxygen plasma

Inductively coupled oxygen plasma was used to study the degradation of Bacillus stearothermophilus. Bacteria were deposited on a silicon wafer substrate and treated by plasma for different periods. The first effect was the removal of the envelope-a protective coating that the bacteria developed during growing. After removing the envelope (capsule), slow etching of the cell wall was observed. Further treatment resulted in the gradual removal of the cell wall, and after 240 s, only ashes remained. The images of plasma interaction steps during the bacteria degradation are presented.