Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water
- First Online:
- 15 Downloads
The combined effects of plasma activated water (PAW) and hydrogen peroxide (H2O2), PAW/HP, in sterilization were investigated in this study. To assess the synergistic effects of PAW/HP, S. aureus was selected as the test microorganism to determine the inactivation efficacy. Also, the DNA/RNA and proteins released by the bacterial suspensions under different conditions were examined to confirm membrane integrity. Additionally, the intracellular pH (pHi) of S. aureus was measured in our study. Electron spin resonance spectroscopy (ESR) was employed to identify the presence of radicals. Finally, the oxidation reduction potential (ORP), conductivity and pH were measured. Our results revealed that the inactivation efficacy of PAW/HP is much greater than that of PAW, while increased H2O2 concentration result in higher inactivation potential. More importantly, as compared with PAW, the much stronger intensity ESR signals and higher ORP in PAW/HP suggests that the inactivation mechanism of the synergistic effects of PAW/HP: more reactive oxygen species (ROS) and reactive nitrogen species (RNS), especially OH and NO radicals, are generated in PAW combined with H2O2 resulting in more deaths of the bacteria.
Unable to display preview. Download preview PDF.
- 6.M. Yamamoto, M. Nishioka, M. Sadakata, J. Electrostatics 56, 73 (2002)Google Scholar
- 19.B. Halliwell, J. Gutteridge, Free Radicals in Biology and Medicine, 3rd ed. (Oxford University Press, 1999)Google Scholar
- 20.L.L. McPherson, Water Eng. Manage. 140, 29 (1993)Google Scholar
- 27.R.P. Haugland, Eugene (OR): Molecular Probes, 6th edn. (1996)Google Scholar
- 28.F. Ullmann, Encyclopedia of Industrial Chemistry, 5th edn. (Verlag Chemie: Weinheim, 1989)Google Scholar
- 29.R.E. Kirk, D.F. Othmer, Encyclopedia of chemical technology, 4th ed. (Wiley-Interscience, London, 1995)Google Scholar
- 30.D.R. Lide, Strengths of chemical bond. 9, 51 (1999)Google Scholar
- 32.NIST Chemical Kinetic Database, http://kinetics.nist.gov/kinetics/index.jsp
- 37.B. Halliwell, J.M.C. Gutteridge, Biochem. J. 1, 210 (1984)Google Scholar
- 41.Y. Katsumura, The chemistry of free radicals in N-centered radicals (Wiley, Chichester, 1998), pp. 393–412Google Scholar
- 43.C.H. Foyer, J. Harbinson, P.M. Mullineaux, in Causes of photooxidative stress and amelioration of defense systems in plants (CRC Press, Boca Raton, 1994), pp. 1–42Google Scholar