Analysis of the inactivation mechanism of bacteriophage ϕX174 by atmospheric pressure discharge plasma

Inactivation technology of viruses by atmospheric pressure discharge plasma has been studied actively. However, the predominant factor in the inactivation is still unclear. Bacteriophages, consisting of only nucleic acids and coat proteins, are suitable for the study of the inactivation mechanism due to their simple structure. In this study, inactivation of bacteriophage φX174, which is resistant to drying stress and has some characteristics similar to influenza virus, was investigated using dielectric barrier discharge (DBD) or corona discharge. We exposed wet or dry bacteriophage φX174 to discharge plasma. It is possible to extract the nucleic acids from the bacteriophage and to assay its plaque forming activity by transfection. Therefore, the damage given to the DNA can be separately analyzed. The coat proteins were also analyzed. Both DNA and coat proteins of plasma-treated φX174 phage were damaged, however, the damages of coat proteins were more significant compared to the DNA damages.