Lactococcus lactis-derived extracellular vesicles: A novel nanodelivery system enhance the properties of nisin Z

Probiotic extracellular vesicles (EVs) have garnered attention as a natural nano-delivery system for food applications. However, studies on using EVs as a food preservative-carrying system are limited. Lactococcus lactis L-WY410 is a promising bacteriocin-producing probiotic strain with the po tential to secrete EVs. This study aims to investigate the potential of L. lactis L-WY410 extracellular vesicles (L-EVs) as a delivery system for preservatives. Notably, nisin Z, class I bacteriocin, was observed within the L-EVs by LC-MS/MS and ELISA analysis. Antibacterial assays demonstrated the antibacterial activity of L-EVs was significantly higher than that of free nisin Z in inhibiting the growth of foodborne pathogens, such as Staphylococcus aureus, Listeria monocytogenes. More importantly, L-EVs exhibited superior activity retention under various environmental conditions (e.g., different pH, temperature, and protease). This study shows the potential of probiotics EVs as a natural nano-delivery system for food preservative application.