Establishment of probiotic associations for foods and feeds

The aim of the study was to design associations of probiotic bacteria using a set of modern methods of microbiological research for the purpose of use in functional food products and feed additives. Strains of lactic acid and propionic acid bacteria were selected according to biological compatibility and absence of competitive interactions. Cultivation and quantification of microorganisms were carried out on MRS medium. Based on the results, 2 consortia of bacteria were constructed containing Lactococcus lactis subsp. lactis 24/48, Lactobacillus рlantarum 578/25, Lactobacillus helveticus 842 (D)-2, Propionibacterium freudenreichii subsp. shermanii As-103/12, Propionibacterium shermanii K-16. The study of biological compatibility of lactic acid bacteria was carried out by drop method. New experimental data on the growth rates of associations and the amount of accumulated biomass at 20 hours of growth were obtained, which is a scientific novelty of this study. It is shown that the character of interstrain interactions is important in the selection of strains for probiotic associations. It was established that the studied strains of lactic acid and propionic acid bacteria in the association should be present in the ratio of 2:1, fermentation with periodic stirring in anaerobic conditions at 37°C and pH 5.9-6.0. Sequential introduction of bacterial cultures is advisable after 3-4 hours of pre-incubation of lactic acid bacteria. Experimental data contain established new regularities. It is noted that for therapeutic and prophylactic effect the concentration of probiotics in dry preparations should be not less than 10 to the extent of 10-12 CFU/g of preparation, so the accumulation of bacterial biomass in the technological process should take into account 10-20% death of the population in the process of drying or concentrating.