Elimination Effect of Airborne Fungi Using Dielectric Barrier Discharges Driven by a Pulsed Power Generator

Abstract

Fungal spores causes various problems, from human to plants diseases. Because they are suspended in air, these fungi are difficult to control. Penicillium italicum is such an airborne fungus, mainly spreading itself through spores, and is responsible for the most problematic postharvest diseases affecting oranges and other fruits. Their elimination when passing through the discharge section of the dielectric barrier discharge was evaluated. Nonthermal equilibrium plasma was generated by applying the pulsed voltage generated with the magnetic pulse compression circuit to the reactor. The elimination and sterilization effects were evaluated via hemocytometer and colony counting method. When discharge was generated, the numbers of spores in the impinger decreased up to 2.5 Log10, but the numbers attached to the reactor increased by electrostatic precipitation. The spores that adhered to the reactors were not inactivated. These results indicate that most of the spores passing through the discharge space were collected in the reactor, and those were not sterilized by the discharge. However, they were not blown by the air flow with and without discharge either. Our results give evidence that an ethylene decomposition system using DBD should prevent postharvest disease caused by airborne fungi by the electric filter and eliminate them from the transportation container.