بررسي اثر باكتري توليد كننده باكتريوسين روي ليستريا منوسايتوژنز و باسيلوس سريوس

The study of effect bacteriocin producing Lactoco ccus lactis on Listeria monocytogenes and Bacillus cereus

Background and purpose: Dairy products often associated with problems such as short shelf life and poor hygiene control. A novel approach is to utilize bacteriocin or bacteriocin producer strains, to control undesirable micro flora as Listeria monocytogenes and Bacillus cereus in foods^ Hence, we studied the effect of nisin like producing Lactococcus lactis against Listeria monocytogenes and Bacillus cereus, in order to compare the isolated strain within different countries. Materials and Methods: In this research we studied the effect of nisin like producing Lactococcus lactis, with producer spot test method. We also used supernatant from 24 h culture of Lactoccus lactis. Moreover, we studied the effect of bacteriocin on Listeria monocytogenes and Bacillus cereus growth curves. Results: The growth of both strains was inhibited by the bacteriocin. Conclusion: According to our results, the bacteriocin could be used in liquid food with bacteriocin added directly or as a starter culture in fermentation. This would inhibit the growth of Listeria monocytogenes; furthermore, Bacillus cereus is used to reduce food poisoning for fermented food products.