摘要:Presently many dairy products are being used in Saudi Arabia. Monitoring and isolation of bacterial activity is of highly significance to sustainable health problems and issues. The objective of the study was to isolate bacteriocin-producing Lactic Acid Bacteria (LAB) from some traditional Saudi food. A total of 50 samples from dairy products, commonly consumed in Saudi Arabia, were screened for presence of natural LAB. The Cell-free Supernatants (CFS) of two LAB isolates exhibited antibacterial activities (inhibition zones >10 mm) against food-borne pathogens ( Lactococcus monocytogenes ATCC 7644, Staphylococcus aureus ATCC 29213 and Salmonella enteritidis ATCC13076). The growth inhibitory substances of CFS were sensitive to proteases (Protenase K and Pepsin) indicating the proteinaceous nature of inhibitors (bacteriocins) produced by the two LAB isolates. Their bacteriocins retained activity after thermal treatments (63°C for 30 min, 100°C for 10 min or 121°C for 15 min) or at pH ranging from 4.0 to less than 6.5. The two LAB isolates were phenotypically identified as Lactococcus lactis subsp. lactis (camels milk) and Lactobacillus paracasei (goats milk). The isolated LAB ( Lactococcus lactis subsp. lactis and Lactobacillus paracasei ) can be used as food preservatives and probiotics since they inhibited well-known food-borne pathogens such as L. monocytogenes and survived acidic conditions (pH 2.5) similar to those of the stomach.