Research of biocidal effect of corona discharges on poly(lactic acid) packaging films

• A PLA film was modified using the method of corona discharges in the air.
• Modification of the surface layer of the PLA film with the corona discharge method resulted in sterilisation of the film.
• The microscopic images microorganisms were taken with the epifluorescence microscope.
• The method of bacterial cell staining consisting in the LIVE/DEAD test was used.

Investigation of the effect of corona discharges on the mortality of the strains of bacteria and fungus: Salmonella enteritidis, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Penicillium chrysogenum is presented. The microorganisms were placed onto a polylactide (PLA) packaging film. The surface layer of that film, with the microorganisms deposited on it, was subjected to modification by the corona treatment in the air, using the modifying unit energy (Ej) ranging from 1 to 20 kJ/m2, and then the count of dead bacteria was determined. Microscopic images were taken to show the effect of the corona discharges on the individual microorganisms.