ENHANCING THE ANTIBACTERIAL EFFECT OF BACTERIOCIN FROM LACTOCOCCUS LACTIS SUBSP. LACTIS USING CHITOSAN NANOPARTICLES

Abstract

Chitosan, a cationic polymer derived from the hot alkali deacetylation of chitin, has numerous biological applications with non-toxicity, biocompatibility and biodegradability. Chitosan nanoparticles were prepared and encapsulated with bacteriocin extracted from Lactococcus lactis subsp lactis to produce chitosan nanoparticles conjugate bacteriocin using ionic gelation method. This formulation was examined for its antibacterial activity representing food bio-preservative against Salmonella typhimurium, Escherichiae coli, Bacillus cereus and Staphylococcus aureus, compared with chitosan nanoparticles, crud chitosan and free bacteriocin.  Agar diffusion method was applied to evaluate the in-vitro drug release, effect of pH and temperature on its stability. The results revealed that the In-vitro release within 24 hours of chitosan nanoparticles conjugate bacteriocin was controlled by about (79%) with cumulative and sustained effect when compared with free bacteriocin (94%). Chitosan nanoparticles conjugate bacteriocin exhibit the highest antibacterial activity (with significant difference p < 0.05) followed by free bacteriocin and chitosan nanoparticles, while crud chitosan was the lowest representing thermal stability (≤ 70ºC) when subjected to low pH. Gram-positive bacteria were more susceptible than Gram-negative bacteria to all of the components. Chitosan nanoparticles contribute successful safe food preservative enhancement when incorporated with bacteriocin against the common food-borne pathogenic bacteria.