In this study, we conducted experiments to investigate the effectiveness of a non-equilibrium Ar-N2 plasma jet generated by a Cold Atmospheric Pressure Plasma Torch (CAPPLAT) at a sinusoidal voltage of 20 kV, frequency of 30 kHz with 10 slm of Ar gas and 100 sccm of N2 gas. Highly environmental stress resistant bacterial endospores of Bacillus subtilis, dried on an agar disc were exposed to the plasma discharge from the CAPPLAT for different durations. The viability of spores after plasma exposure was checked by counting CFUs by serial dilution method. We also measured the amount of released DPA (dipicolinic acid, pyridine-2, 6-dicarboxylic acid), which is exclusively found in endospore protoplast (cortex), to confirm the disintegration of the cortex. We could successfully inactivate a population of Bacillus endospores of about 1.0 × 107 to 4.0 × 107 spores/ml.
Oxidative modification and electrochemical inactivation of Escherichia coli upon cold atmospheric pressure plasma exposure
