Evaluation of protegrin-1 for meat preservation via peptide treatment and transgenic expression

Antimicrobial peptides (AMPs), such as protegrin-1 (PG-1), have attracted attention as natural bacterial growth inhibitors. In this study, we evaluated the antimicrobial efficacy of PG1 in meat models contaminated with 5000 colony-forming units per gram of common spoilage bacteria. Under refrigerated storage at 4°C, PG-1-overexpressing transgenic (PG-1 Tg) muscle tissues showed a one-log reduction in bacterial counts of both S. aureus and B. cereus compared with respective inoculated wild-type (WT) muscle tissues on days 7 and 14. Uninfected PG-1 Tg muscle tissues maintained negligible bacterial counts throughout the 14-day storage period. Under room temperature conditions, PG-1 Tg tissues showed reductions of approximately one to two log units on day 3 and two to five log units on day 7 in bacterial counts compared with inoculated WT muscle tissues. In addition, PG-1 displayed lower MIC values and greater stability than nisin across pH (3–9), temperature (25–90°C), and proteolytic ranges, supporting its potential as a natural bacterial growth inhibitor for meat products. Although regulatory considerations remain regarding the use of AMP-expressing transgenic animals, this strategy may represent an innovative and cost-effective approach to improving meat preservation and reducing microbial spoilage in the food industry.