Characterization of lactic acid bacteria isolated from traditionally made Serbian Cheese and evaluation of their antagonistic potential against Enterobacteriaceae

In this article, the presence and physiological characteristics of lactic acid bacteria (LAB) isolated from traditionally made cheese from Southeastern Serbia were examined. Three samples, from different households, were obtained in spring. The screening of antagonistic potentials, using agar-well diffusion method, was evaluated. Briefly, three different genera of LAB (Enterococcus [32%], Lactococcus [53%], and Lactobacillus [15%]) were identified. The members of the genus Enterococcus were Enterococcus faecium and Enterococcus faecalis. The member of genus Lactococcus was Lactococcus lactis subsp. lactis var. diacetylactis. The members of genus Lactobacillus were Lactobacillus fermentum, Lactobacillus plantarum, and Lactobacillus paracasei subsp. paracasei. The antagonism of LAB on the growth of Escherichia coli ATCC 25922, Proteus mirabilis ATCC 12453, Klebsiella oxytoca KGPMF1, Klebsiella ornithinolytica KGPMF8, and Aeromonas hydrophila was examined. All tested isolates inhibited the growth of at least one indicator strain with growth inhibition zone from 10 to 21mm. Results indicated that LAB demonstrated the potential of food biopreservation. Practical applicationsTraditionally made cheeses represent excellent source of unexplored microflora, especially of autochthonous lactic acid bacteria (LAB). In cheese from Sokobanja, the isolated LAB genera were Lactobacillus sp., Lactococcus sp., and Enterococcus sp. Also, the physiological activity of LAB, as well as their interaction with enterobacteria, which also was isolated from the mentioned cheese, was investigated. The results of this study demonstrated potential of LAB to interact agonistically with the growth of enterobacteria, which was important due to the well-known fact that enterobacteria could affect the organoleptic properties of cheese. LAB showed potential of food biopreservation. Further investigation should include antagonistic potential related to food-borne bacteria and the mechanisms of action.