Antimicrobial activity of goat’s milk fermented by single strain of kefir grain microflora

Abstract

The aim of the study was to assess the antibacterial properties of bioactive compounds released during the fermentation of goat’s milk by selected bacterial strains that are part of the kefir grain microflora. The material used in the experiments was kefir grain microflora (Lactobacillus kefiranofaciens subsp. kefirgranum DSM 10550, Lactobacillus kefiri PCM 2501, Lactobacillus parakefiri DSM 10551, Lactobacillus brevis PCM 488, Lactobacillus delbrueckii subsp. lactis PCM 2611), goat’s and cow’s milk and whey from these kinds of milk. The antimicrobial activity was tested against E. coli, Salmonella, Micrococcus luteus and Proteus mirabilis. Based on the experiments, it was found that during the fermentation of whey and goat's milk, bioactive substances were released, which inhibit the growth of indicator microorganisms by up to 8 logarithmic cycles.