Mycoidesin, a novel lantibiotic, exhibits potent bacteriostatic activity against Listeria monocytogenes and effectively controls its growth in beef

Abstract

Listeria monocytogenes can cause severe listeriosis, with the consumption of contaminated food being an important route of its transmission. Biopreservatives can be used for the prevention and control of L. monocytogenes in food. In this study, we identified a novel lantibiotic, mycoidesin, with potent bacteriostatic activity against L. monocytogenes. It exhibited 4- to 16-fold higher bacteriostatic activity against the L. monocytogenes strains than nisin A. Analysis of the mode of action of mycoidesin revealed that it exerted bacteriostatic activity against L. monocytogenes ATCC 19111 at low and high concentrations (1×–32× MIC, 0.39–12.5 µM). It blocked cell wall synthesis by binding to Lipid II and inhibiting the growth of L. monocytogenes. For other sensitive strains, such as Bacillus cereus CMCC 63301, mycoidesin exerted a bacteriostatic effect at a low concentration (1× MIC, 1.56 µM) via the same mechanism, whereas it exerted a bactericidal effect at high concentrations (2×–8× MIC, 3.13–12.5 µM), which can damage the cell membrane and cause cell death. The stability test showed that mycoidesin had increased stability compared to nisin A. Additionally, mycoidesin showed low cytotoxic and hemolytic activity. Furthermore, mycoidesin effectively inhibited the growth of L. monocytogenes in beef and delayed the decline in beef quality. Our study demonstrates the potential of mycoidesin as a biopreservative to prevent L. monocytogenes contamination and improve the safety of meat and meat products in the food industry.