Antagonistic effect of bacteriocines produced by lactobacilli isolated from West Azerbaijan's Kuppeh cheese

In this study, isolation and identification of bacteriocin producing strains from west Azerbaijan Kuppeh cheese is investigated. For this purpose, 8 samples of cheese were collected from different parts of west Azerbaijan. 36 out of 48 colonies of isolated Lactic Acid Bacteria (LAB) showed high antimicrobial activity against the indicator strains. In order to avoid of antimicrobial effect of organic acid produced by LAB, in this step, the pH levels of supernatant were adjusted to 6.5-7. After pH adjustment, only 12 isolated strains showed antimicrobial activity. A comparative study using morphological and biochemical tests demonstrated that 2 isolated strains were belonging to Lactobacillus plantarum, 1 belonging to Lactobacillus brevis and 1 belonging to Lactobacillus paracasei. The result of partial purification and electrophoresis of bacteriocin indicated that the molecular weight of proteins were 15, 40 and 50 kDa.