The Combination of Plasma-Processed Air (PPA) and Plasma-Treated Water (PTW) Causes Synergistic Inactivation of <i>Candida albicans</i> SC5314

Abstract

Microwave-induced plasma was used for the generation of plasma-processed air (PPA) and plasma-treated water (PTW). By this way, the plasma was able to functionalize the compressed air and the used water to antimicrobial effective agents. Their fungicidal effects by single and combined application were investigated on Candida albicans strain SC5314. The monoculture of C. albicans was cultivated on specimens with polymeric surface structures (PE-stripes). The additive as well as the synergistic fungicidal potential of PPA and PTW was investigated by different process windows of plasma exposure time (5–50 s) and sample treatment time with PPA/PTW (1–5 min). For a single PTW or PPA treatment, an increase in the reduction factor with the indicated treatment time was observed (maximum reduction factor of 1.1 and 1.6, respectively). In comparison, the combined application of PTW and then PPA resulted in antagonistic, additive and synergistic effects, depending on the combination. An application of the synergistically acting processes of PTW for cleaning and PPA for drying can be an innovative alternative to the sanitary processes currently used in production plants.

Keywords

• antimicrobial
• atmospheric pressure
• decontamination
• microwave discharge
• cold plasma