In vitro evaluation of antimicrobial potential and ability of biofilm formation of autochthonous Lactobacillus spp. and Lactococcus spp. isolated from traditionally made cheese from Southeastern Serbia

Abstract

© 2018 Wiley Periodicals, Inc. The presence, biochemical and physiological characteristics of Lactobacillus and Lactococcus species isolated from traditionally made cheese from Southeastern Serbia (Sokobanja), was investigated. The screening of their antimicrobial potentials, using agar-well diffusion method, and the ability of biofilm formation, using crystal violet method, was evaluated. The cheese samples, from different households, were obtained during the summer and the autumn. Chemical characteristics of cheese samples were examined. The members of genus Lactobacillus were: Lb. fermentum, Lb. brevis, and Lb. plantarum. The members of genus Lactococcus were: Lc. lactis subsp. lactis and Lc. lactis subsp. lactis biovar. diacetylactis. The antagonism of Lactobacillus and Lactococcus isolates on the growth of some Gram-negative bacteria, isolated from the same cheese, was examined. The zones of growth inhibition ranged from 10 to 26 mm. The ability of biofilm formation of isolates was strains-specific. Lactobacillus (KGPMF 28, KGPMF 29, KGPMF 35) and Lactococcus (KGPMF 23 and KGPMF 26) isolates demonstrated the potential for further investigation in natural preservation of food. Practical applications: Lactic acid bacteria, which can be found in traditional dairy products, presents unique and autochthonous microflora responsible for fermentation and quality of dairy products. These bacteria often have a great potential in natural food preservation, but their number and diversity are depending of season, vegetation, and the nutrition of animals. In this paper, the seasonal differences in bacterial community (especially community of lactobacilli and lactococci) between cheese samples, were investigated. In addition, the antagonism against some enterobacteria, which can affect the hygienic safety of cheese, was screened. Also, it was showed that some isolates had the ability of biofilm formation. Further investigation need to include the potential of isolates to be uses like probiotic or starter cultures.