Potential use of a bacteriocin-like substance in meat and vegetable food biopreservation

Bacillus spp. produces a large number of antimicrobial peptides and includes a variety of species of industrial importance. The aim of the present study was to evaluate the shelf-life extension of fresh beef and lettuce by applying crude extract of a bacteriocin-like substance (CBLS) produced by a native strain of Bacillus cereus P9. Food samples were sprayed with the CBLS and stored at 4°C. Microbiological analyses (count of mesophilic and psychrotrophic aerobic bacteria, total coliforms and molds and yeasts) and pH determination were performed on samples after 0, 3, 6, 9 and 12 days. In addition, the effect of the CBLS on the growth of a pathogenic bacteria added to the food was evaluated. A significant reduction of mesophilic and psychrotrophic aerobic bacteria counts were found in meat treated with crude bacteriocin extract. In adition, lettuce samples inoculated with B. cereus and treated with the CBLS, presented a reduction of this microorganism compared to control after 4 h of storage.