The behaviour of L. innocua present in the mixed culture, inoculated on the surface of Port Salut cheese is shown in Fig. 2b. The film NANI caused a bactericidal effect on L. innocua until the first 144 h and then, the bacteria resumed its growth and reached a final count of approximately 4 log cycles lower than those observed for cheeses covered with CNANI and CF films at the end of the storage. Direct application of antimicrobials (DA) had a bacteriostatic effect along the whole test, maintaining the initial count of 4 log cycles. It is interesting to compare the nisin activity for the different forms of application (NANI vs DA). For DA, proteins and lipids present in cheese might have interacted with nisin decreasing its effectiveness (Sanjurjo, Flores, Gerschenson, & Jagus, 2006). Conversely, the support of antimicrobials in the film, allowed a slow release of nisin, reducing the interactions while preserving antimicrobial availability over the whole time of the assay.