Study On Sterilization Mechanism Of Low Temperature Plasma Activated Water

In this study,plasma activated water was prepared by dielectric barrier discharge plasma technology,and its p H value,conductivity,UV spectrum,nitrite content and H₂O₂ content were measured.The bacteria（Escherichia coli and Staphylococcus aureus）were taken as the main research object,the survival of microorganisms before and after treatment was studied by colony counting method under different power supply,preparation time and the ratio of bacterial suspension to plasma activated water.At the same time,the surface morphology of the cell was observed by scanning electron microscope,the leakage of DNA and protein,the production of malondialdehyde and the expression of related membrane genes were detected.The results showed that plasma activated water contained a large number of active substances,such as charged particles,ions and so on.With the increase of treatment power,preparation time and the ratio of bacterial suspension to plasma activated water,plasma activated water had obvious bactericidal effect on Escherichia coli（E.coli）and Staphylococcus aureus（S.aureus）.Plasma activated water caused DNA and protein leakage and induced the production of malondialdehyde.Meanwhile,the gene encoding I integrase of E.coli treated with plasma activated water was down regulated by 0.24 times,and fhl ART,flh CRT and dna ERT were reduced by 0.00001,0.01 and 0.13 times respectively,which destroyed the small molecule entry and exit channels of E.coli,reduced the biofilm forming ability and stress response ability of E.coli,and made E.coli unable to survive.In this study,plasma activated sodium hypochlorite solution was prepared by dielectric barrier discharge plasma technology,and its p H value,conductivity and UV spectrum were measured.Taking bacteria（E.coli and S.aureus）as the main research object,the survival of microorganisms before and after treatment was studied by colony counting method under different power supply power,preparation time and sodium hypochlorite concentration.Simultaneously,the surface morphology of the bacteria was observed by scanning electron microscope,and the leakage of DNA and protein and the production of malondialdehyde were detected.The results showed that plasma activated sodium hypochlorite solution contained a large number of active substances,such as charged particles,ions and so on.With the increase of treatment power,preparation time and sodium hypochlorite concentration,plasma activated sodium hypochlorite solution had obvious bactericidal effect on E.coli and S.aureus.Plasma activated sodium hypochlorite solution caused DNA and protein leakage and induced the production of malondialdehyde.