ANTIMICROBIAL ACTIVITY OF THE PROBIOTIC STRAIN LACTOBACILLUS DELBRUECKII SSP. BULGARICUS GB OF HUMAN ORIGIN AGAINST PATHOGENS

Abstract

Probiotics help restore the balance of the gastrointestinal microflora, but only strains with certain properties can be included in their formulations. One of the requirements for a strain to be probiotic is to exhibit inhibitory activity against pathogens.The antimicrobial activity of the strain Lactobacillus delbrueckii ssp. bulgaricus GB against the pathogens E.coli ATCC 25922, E.coli ATCC 8739, Salmonella abony NTCC 6017, Salmonella sp., Staphylococcus aureus ATCC 25293 and Proteus vulgaris J is determined by joint cultivation at 37±1°C.  Lactobacillus delbrueckii ssp. bulgaricus GB inhibits the growth of the pathogens - for 60 - 72 hours the numbers of viable cells of the pathogens are reduced. It has been shown that the changes in the proportions in the mixed populations are due to the accumulation of lactic and other organic acids which acidify the medium and change the conditions for the growth of the pathogens, leading to reduction of the number of viable cells of the pathogens. The demonstrated inhibitory activity of Lactobacillus delbrueckii ssp. bulgaricus GB makes the strain potentially probiotic and after additional studies it can be included in the composition of probiotics and functional foods.