Use Of Baceriocin Producing Lactobacilli Strains From Fruits And Vegetables In Food Preservation

Bacteriocin producing bacteria plays an important role in food preservation. The bacteriocin producing Lactobacilli strains were isolated from different fruits and vegetables from the local markets of Punjab, Pakistan. The bacterial were grown on MRS selective media and their biochemical activity was checked further for the confirmation of Lactobacilli. Antimicrobial activity of these selected strains was checked against different pathogens. For further characterization of bacteriocin production by Lactobacilli, the activity of bacteriocin at different parameters such as at different temperature and pH and the proteolytic activity were checked. Antibiotic activity of bacteriocin producing Lactobacilli was also checked against ampicillin, ciprofloxacin, streptomycin and tetracycline. Out of total strains isolated, 10 strains were selected as Lactobacilli on the basis of their morphology and biochemical characterization. 80% of strains showed zone of inhibition with the best zone being shown by Ct2 (14 mm) against E.coli (ETCC) and A3 (14 mm) against Enterobacteria. Bacteriocin ability of these selected strains was found maximum at 7 pH and 35ºC. The strain T1 was sensitive to ampicillin, ciprofloxacin and streptomycin and strain T2 was resistant to ciprofloxacin, streptomycin and tetracycline. The best characterized strains were selected for fruit juice preservation where lactobacilli producing bacteriocin prevent the growth of other food spoiling bacteria.