Investigation of the metabolite composition of lactic acid bacteria strains on the basis of a probiotic drug

Introduction. Lactic acid bacteria synthesize antimicrobial substances of various nature: acids, alcohols, diacetyl, reuterin, hydrogen peroxide, carbon dioxide, etc. The Food and Drug Administration (USA) and the European Food Safety Authority have recognized lactic acid bacteria as safe for human and animal health. In this regard, they can also be of great importance as producers of amino acids, including essential ones. The purpose of the study is to carry out a comparative analysis of the organic and amino acids production by strains of probiotic bacteria. Material and methods. Selected strains of lactic acid bacteria were used: Lactobacillus plantarum IMV B-7344, Lactobacillus casei IMVB-7343, Lactobacillus acidophilus RCAM 01850, Lactococcus lactis subsp. lactis RCAM 02909, Lactococcus lactis subsp. cremoris RCAM 05396, Streptococcus thermophilus RCAM 02910. Analysis of amino acids and organic acids was carried out with capillary electrophoresis "Capel 105" and the program "Multichrom". Results. All the studied strains have a fermentation-type metabolism with formation of lactic, acetic, butyric and caproic acids with a total production level of up to 29.06 g/l. The production of malic and succinic acids by lactobacilli (0.06-0.59 g/l) should be noted, as opposed to lactococci and streptococcus, which do not synthesize these acids even in trace amounts. The content of free amino acids in the submerged cultivation process was 35.88-49.06 g/l, including essential 11.81-21.21 g/l. Significant amounts of leucine and isoleucine (8.63-17.20 g/l), glutamine (9.83-10.60 g/l) and proline (5.42-7.48 g/l) were noted in the culture fluid, with the first two being essential. Conclusion. The data obtained must be taken into account when developing multicomponent probiotics, since these factors largely determine the effectiveness of the impact on pathogenic microorganisms and humans.