Feeding-Gas Effects of Plasma Jets on Escherichia coli in Physiological Solutions

The effects of air and N2 plasma jets on Escherichia coli inside four different physiological solutions and deionized water are reported here. The feeding gases are found to influence the plasma compositions, the interactions with the liquids, and the subsequent bactericidal effects depending on the aqueous solutions to which they are exposed. Air plasma enhances the bactericidal effects of deionized water and saline by acidification. On the other hand, N2 plasma induces higher toxicity in phosphate buffered saline by generating more electrons. Little bactericidal effects of cell culture media and blood plasma may be due to the slight change in the pH and due to electron scavenging by organic components. Taken together, our study provides additional insight into the basic interactions between plasma and cells in physiological solutions. [GRAPHICS] .