Glow Discharge Plasma Sterilization of Prokaryotic Microorganism Through Electrostatic Plasma

Abstract

Sterilization/disinfection of target bacteria – Bacillus Subtilis – is investigated using plasma sterilization process which involves both Dielectric Barrier Discharge Plasma (DBD) and Glow Discharge Plasma. The purpose of this work is to identify the optimum parameters for sterilization of the target microorganism involving the use of electrostatic plasma. B. Subtilis is a diverse bacteria species found to be highly resistant dormant endospores. [2] Capable to growth in diverse environments – terrestrial and aquatics – including in the gastrointestinal tract of animals and humans. [1], [2] The sterilization was carried out at PUPR Plasma Engineering Laboratory in which the voltage (460-500 Volts) and time intervals (15, 10, 5, 1 minutes) were varied. The system was pumped down to a vacuum level of 10-1 Torr during the sterilization process. Flowing Plasma was created in the chamber and interacted with the corning glass having direct contact with the bacteria. The flowing afterglow of the reduced pressure in ionized air provides photons over a broad ultraviolet wavelength range as the main biocidal agent of the B. Subtilis. [1] A 70% effectiveness of the bacteria sterilized in Glow Discharge Plasma was observed while The DBD was found non effective on the Bacillus.