bactericide effect of atmospheric plasma of flat and comb electrodes on escherichia coli

objective: the current study was undertaken to examine the bactericide effects of atmospheric plasma produced by flat and comb electrodes on e.coli. materials and methods: dc (20 w) and ac (500 w) power supplies, flat and comb electrodes, insulator and oxygen gas were used to produce atmospheric plasma. bactericide effects of the atmospheric plasma were studied on e.coli on sterilized plate placed on ice powder, at 3 mcfarland concentration. results: flow of the atmospheric plasma produced by flat electrodes and ac power supply reduced e.coli population by 100% during 15 minutes. but the flow of the atmospheric plasma produced by comb electrodes reduced e.coli population by 12% in 15 minutes and 51% in 30 minutes. in addition, the flow of atmospheric plasma produced with dc power supply with flat and comb electrodes reduced e.coli population about 50% and 17%, respectively in 30 minutes. statistical analysis indicated significant differences (p<0.005) between bactericide effects of atmospheric plasma from dc and ac power supply in 15 and 30 minutes. conclusion: flat electrode structures in both down and high plasma atmospheric sterilize and control e.coli populations. we recommend further studies on examining the bactericide properties of atmospheric plasma on other bacteria, especially staphylococcus aureus and bacillus subtilis.