Polycaprolactone film functionalized with bacteriophage T4 promotes antibacterial activity of food packaging toward Escherichia coli.

Bacteriophages (phages) have been extensively utilized as antibacterial agents in the food industry because of their host-specificity. However, their application in polymer films has been limited because of the lack of a strong attachment method for phage to the surface. We developed an antibacterial film by covalently immobilizing Escherichia coli (E. coli)-specific phage T4 on a polycaprolactone (PCL) film. The chemical bond formation was confirmed by XPS analysis, and the covalent attachment of phage T4 effectively inhibited E. coli growth even after external stimulation of the film by sonication. When applied as a packaging film for raw beef inoculated with E. coli O157:H7, the chemically functionalized PCL film showed approximately 30-fold higher bacterial inhibitory effects than the film with physically adsorbed phage T4. These results indicate the promising application potential of chemically functionalized PCL film with phage T4 as an antibacterial food packaging material against the foodborne pathogen E. coli.