Bactericidal Effects against S. aureus and Physicochemical Properties of Plasma Activated Water stored at different temperatures

• DOI: 10.1038/srep28505
• Publication Date: 2016-06-27T09:52:46Z
• Authors: Jin Shen; Ying Tian; Yinglong Li; Ruonan Ma; Qian Zhang; Jue Zhang; Jing Fang
• Keywords: Atmospheric Pressure Plasmas; Composite material; Radiology, Nuclear Medicine and Imaging; Staphylococcus aureus; Plasma Gases; Nitrite; Organic chemistry; Nitrate; Biochemistry; Article; Food science; Engineering; 0404 agricultural biotechnology; Electrohydrodynamic Jet Printing and Nanoparticle Encapsulation; Health Sciences; FOS: Electrical engineering, electronic engineering, information engineering; Genetics; Electrical and Electronic Engineering; Biology; Nitrates; Bacteria; Applications of Plasma in Medicine and Biology; Electron Spin Resonance Spectroscopy; Temperature; Water; Scanning electron microscope; Hydrogen Peroxide; 04 agricultural and veterinary sciences; Hydrogen-Ion Concentration; Hydrogen peroxide; Materials science; Anti-Bacterial Agents; Nuclear chemistry; Chemistry; Reduction potential; FOS: Biological sciences; Physical Sciences; Microscopy, Electron, Scanning; Medicine; Nitrogen Oxides; Surgery; Therapeutic Applications of Molecular Hydrogen Therapy; Oxidation-Reduction; Inorganic chemistry

AbstractWater activated by non-thermal plasma creates an acidified solution containing reactive oxygen and nitrogen species, known as plasma-activated water (PAW). The objective of this study was to investigate the effects of different storage temperatures (25 °C, 4 °C, −20 °C, −80 °C) on bactericidal activities againstS. aureusand physicochemical properties of PAW up to 30 days. Interestingly, PAW stored at −80 °C yielded the best antibacterial activity againstStaphylococcus aureus, 3~4 log reduction over a 30-day period after PAW generation; meanwhile, PAW stored at 25 °C, 4 °C and −20 °C, respectively, yielded 0.2~2 log decrease in cell viability after the same exposure and storage time. These results were verified by scanning electron microscope (SEM). The physicochemical properties of PAW stored at different temperatures were evaluated, including pH, oxidation reduction potential (ORP) and hydrogen peroxide, nitrate, nitrite anion and NO radical levels. These findings suggested that bacterial activity of PAW stored at 25 °C, 4 °C, −20 °C decreased over time and depended on three germicidal factors, specifically ORP, H2O2and NO3−. Moreover, PAW stored at −80 °C retained bactericidal activity, with NO2−contributing to bactericidal ability in association with H2O2. Our findings provide a basis for PAW storage and practical applications in disinfection and food preservation.