Antagonistic properties and biocompatibility as important principles for development of effective and biosafety probiotic drugs

Antagonistic properties and peculiarities of inter-strain interactions of probiotic microorganisms were investigated. The study of the antagonistic activity of probiotic strains was carried out by the methods of perpendicular strokes (or delayed antagonism) and the diffusion method (block modification) in relation to opportunistic and pathogenic microorganisms. Most probiotic strains had moderate to high antagonistic activity against both gram-positive and gram-negative pathogens. The results obtained allowed us to select the most active strains, namelyL. plantarum AS-41, L. acidophilus A-14, B. subtilis S-2andB. subtilis S-18, which have a high probiotic potential. To assess biocompatibility, the method of co-cultivation of the selected strains on a modified agar MRS medium was used. The strains that showed biocompatibility of the type “mutual neutrality” or “contact progression” were selected to create a consortium of probiotic microorganisms. Further study of the investigated strains of probiotic bacteria opens up the possibilities of their use for the manufacture of a combined preparation for veterinary purposes, for the prevention and treatment of diseases of the gastrointestinal tract of farm animals.