A study on application of wild Lactococcus lactis strains as starter in reduction of Staphylococcus aureus in brined cheese

As the technological point of view, cheese is a nutritious environment for growth of several of foodborne pathogens such as Staphylococcus aureus. Although, application of chemical and natural preservatives is common in prolongation of shelf-life of dairy products, so many researches are still running to find alternatives solutions. In this study, the effect of three strains of lactococcus lactis named as JP51, FK23 and DC103 was evaluated on viability of S. aureus in cheese. The produced cheese samples were analyzed for chemical composition and viability of S. aureus during period of 20 days of storage. The results showed that all three strains were able to significantly reduce the number of viable S. aureus in comparison to control. According to our results, the cheese manufactured by strain JP51 had the lowest number of S. aureus (2.00 log cfu/g) after 20 days of storage. Subsequently, current study showed that L. lactis isolate JP51 can be considered as potent natural antibacterial starters for cheese production. However, it would be necessary to evaluate its effect on physical and sensorial properties of cheese.