Abstract

According to the definition of probiotics by the Food and Agriculture Organization of the United Nations/World Health Organization, “probiotics are live microorganisms, which when administered in adequate amounts confer a health benefit on the host”. Microorganisms that are probiotics in humans include Enterococci, Bifidobacteria and lactic acid bacteria, such as Lactobacilli, Lactococci and Streptococci. This research was conducted to determine the presence of antibacterial effects among the probiotics isolated from different bioyoghurts against some common bacterial pathogens. Lactobacillus sp., Streptococcus sp. and Bifidobacterium sp. from yoghurts containing probiotics were isolated and examined for their antibacterial effects against Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa. The modified agar overlay method was used for determination of the presence of antibacterial effects among the isolated probiotics. Results showed the presence of antibacterial effects among the probiotics that were isolated from bioyoghurts. The spectrum of their antibacterial effects varied against the selected pathogen. Antibacterial effects are one of the most important selection criteria for probiotics, and the verified antibacterial activity of the probiotics supports the development of these functional foods as a key to the improvement of health in the consuming public.

Key words: Probiotics, bioyoghurts, Lactobacillus spp., Bifidobacterium spp., antibacterial effects.