Inhibition of listeriamonocytogenes in a model cheese samples using in situ produced bacteriocins by lactic acid bacteria

Zulfigarova Vusala Shahin, Gulahmаdov Saib Gurban, Bakhshaliyeva Konul Farukh

The growth dynamics of Lactobacillus delbrueckii spp. lactis A7 and Enterococcus faecalis S5 and the intensity of in situ production of bacteriocins, as well as the possibility of using them to inhibit the growth of L. monocytogenes 302 during the maturation of model cheese samples were studied. With the same amount of initial inoculum (log 3 CFU/g of cheese), 7.2 log units of live cells of L. delbrueckii lactis A7 and 6.1 log units E. faecalis S5 were found at the end of the cheese ripening period. The maximum titer of bacteriocin A7 and enterocin S5 in the medium, which was detected at the end of the first week of the maturation process, was 1200 IU/g and 2200 IU/g, respectively. In the absence of inhibitory factors, the amount of primary inoculum L. monocytogenes 302 in cheese increased 2.5 times. L. delbrueckii spp. lactis A7 and E. faecium S5, as well as bacteriocin A7 and enterocin S5, inhibited the growth of L. monocytogenes in cheese by 40%, 63%, 61% and 74%, respectively.

Keywords:cheese, Listeria monocytogenes, biocontrol, bacteriocin