| Summary: | This study aimed to evaluate the antimicrobial activity of both cells, and cell-free supernatants (CFS) of 7 selected lactic acid bacteria (LAB) strains belonging to <i>Limosilactobacillus fermentum</i> (4 strains), <i>Lacticaseibacillus paracasei</i> (1 strain), <i>Lacticaseibacillus rhamnosus</i> (1 strain), and <i>Enterococcus faecium</i> (1 strain) species, against <i>Listeria monocytogenes</i>, <i>Escherichia coli, Salmonella</i> Typhimurium, <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>, by both the agar-well diffusion and co-culture methods. In addition, probiotic and safety traits were also detected. Great variability was detected on antimicrobial effects, whereas all tested strains were found sensitive to most of the tested antibiotics, and without any DNase, gelatinase, or hemolytic activity. Moreover, strains showed excellent survival in acidic conditions and exhibited tolerance to pepsin and bile salts. Based on the in vitro results, the CFSs of two selected <i>L. fermentum</i> strains were applied, in a mixed solution, as bio-preservative into minimally processed pomegranate arils, inoculated with a cocktail of <i>L. monocytogenes</i> and <i>E. coli</i>. Samples, packaged in an ordinary atmosphere, were analyzed during refrigerated storage, for up to 12 days, for physicochemical (as weight loss, texture, color, pH, total soluble solids and organic acid content) and for microbiological traits. Results revealed the effectiveness of CFS, up to 12 days, in reducing weight loss and microbial growth, without any significant effect on texture, total soluble solid content and color, found comparable to the acid citric treatment, highlighting the multi-functional potential of selected probiotic strains.
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