Sterilization effect of atmospheric plasma on Escherichia coli and Bacillus subtilis endospores
1Department of Molecular Science and Technology, Ajou University, Youngtong-Gu, Suwon, Korea.
Aims:
Escherichia coli and Bacillus subtilis spores were treated with an atmospheric plasma mixture created by the ionization of helium and oxygen to investigate the inactivation efficiency of a low-temperature plasma below 70 degrees C.
Methods And Results:
An electrical discharge plasma was produced at a radio frequency (RF) of 13.56 MHz, connected to a perforated circular electrode with a discharge spacing of 1-15 mm. The discharge gas was helium with 0-2% oxygen. For the plasma treatment, a dried E. coli cell or B. subtilis endospore suspension on a cover-glass was exposed to oxygen downstream of the plasma from holes in an RF-powered electrode. The sterilization effect of the RF plasma was highest with 0.2% oxygen, corresponding to the maximum production of oxygen radicals.
Conclusions:
Oxygen radicals generated by RF plasma are effective for the destruction of bacterial cells and endospores.
Significance And Impact Of The Study:
Low-temperature atmospheric plasma can be used for the disinfection of diverse objects, especially for the inactivation of bacterial endospores.
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