Films were prepared with 0.2% (w/v) gellan gum, 1% (w/v) citric pectin, 0.5% (w/v) glycerol, 5 mM CaCl 2 , 0.05 M Ethylenediaminetetraacetic acid (EDTA), and different concentrations of an antimicrobial activity-concentrated supernatant (AMC) obtained from fermentations of Streptococcus infantarius, which produces bacteriocin-like inhibitory substances (i.e., treatments F1, F2 and F3 with 75, 90 and 120 arbitrary units (AU)/mL, respectively). The treatments were based on a minimum-inhibitory-concentration (i.e., AMC, 90 AU/mL, plus EDTA, 0.05 M) for Escherichia coli, Staphylococcus aureus and Listeria monocytogenes growing in brain-heart-infusion medium at 35 °C. The films hindered the bacterium growth in selective media: E. coli-MacConkey, S. aureus-Baird Parker and L. monocytogenes-Dxford, during 30 days at 25 °C. Moreover, the F2 films entirely inhibited the growth of the tested bacteria in a Mexican cheese medium, in 7-day cultures at 35 °C; contrariwise, controls with no film exhibited bacterial growths in the range 10 ), 1.9/1.2.Keywords: lactic acid bacterium; bacteriocins; biopreservation; mechanical properties; gas permeability.