Study on the disinfection mechanism of microorganisms by electron beam irradiation based on PMA-qPCR analysis
In this study,the PMA-qPCR conditions for three kinds of indicating microorganisms were obtained and optimized,a gradient dose of 1 to 5 kGy was set to conduct electron beam irradiation,PMA-qPCR test and SPSS software were used to analyze the variance of RQ value,and the mechanism of radiation damage to cell membrane permeability was inferred.The results showed that the optimum PMA concentration of Escherichia coli,Staphylococcus aureus and Bacillus subtilis var.niger was 50μmol/L,and the optimum photolysis time was 30 min,15 min and 60 min,respectively.The irradiation dose(0～5kGy),PMA treatment and the interaction between them were significant(P≤0.001).The RQ val-ues of the PMA-treated groups for the three microorganisms were all lower than those of the untreated groups(except for the 3～5 kGy treatments of Bacillus subtilis).Additionally,with the increase in irradia-tion dose,the RQ values after PMA treatment generally showed a decreasing trend among the three mi-croorganisms.It was inferred that the electron beam irradiation is likely to destroying the cell membrane of three microorganisms.The recommended dose for inactivation of the three microorganisms is 5 kGy.
Electron beamirradiationEscherichia coliStaphylococcus aureusBacillus subtilis var.nigerPMA-qPCRdisinfection
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