Identification and characterization of a novel pH and heat stable bacteriocin-like substance lactococcin036019 with food preserving potential

Bacteriocins are promising alternatives to traditional food preservatives to control food borne pathogen. However, most bacteriocins lose the majority of activity when the pH environment turns to neutral or alkaline, this severely limits the application of bacteriocins in food preservation. This study aims to screen and identify heat-stable and wide pH range active bacteriocin antagonizing Staphylococcus aureus. Of the 198 bacterial strains, Lactococcus lactis NCU036019 with significant anti-Staphylococcus aureus activity was discovered and corresponding lactococcin036019 was purified and characterized. Treatment by heat at 121°Cfor 30 min did not affect the antibacterial activity of lactococcin036019 and it was pH 2–10 active. Moreover, lactococcin036019 displayed remarkable inhibitory effect on Staphylococcus aureus in milk and outstanding stability during storage. Multiple assays revealed that lactococcin036019 exerted anti-Staphylococcus aureus activity by prevention of biofilm formation, pore-forming, and inhibition of cell division. This study provides strong evidence that the novel lactococcin036019 has great potential in food application.