Rusnak N. Intracellular metabolism of the microbial populations in the animal gastrointestinal tract under the exogenous factors effect

metabolic processes in the cells of bacteria pure strains, bacterial complexes and mixed microbial populations of gastrointestinal tract in various species of animals. Purpose - to find out the peculiarities and the role of intracellular metabolism of mixed microbial populations and bacteria pure strains of gastrointestinal tract in various species of animals under the effect of some antimicrobial compounds (PCP) and substances with protective properties (Kl) on the ground of change of using biosubstrates different by accessibility and nutrient value. Methods - biochemical (gas-chromatographic definition of final products of microbial metabolism and spectrophotometric determination of metabolites concentration and enzymes activity), biological-technological (analysis of productive qualities of animals), microbiological (obtaining the samples of microbial populations and their cultivation), pharmacological (determination of toxicity level of various doses of biocide) and statistical (authenticity of results obtained) methods. Novelty - it was established for the first time that different doses of antimicrobial compound PCP exert unequal inhibiting effect on metabolic reactions of ruminant mixed microbial populations formed on biosubstrates different by nutrient accessibility. Supplement of natural sorbents (Kl) into cultural medium on the ground of PCP inhibiting influence has twice bigger protective effect where microbial populations were formed on more accessible biosubstrates. Even the low doses of biocide (up to 40 µmol) reliably (p < 0,05) decrease the activity of intracellular enzymes of bacterial complex of rumen microbial population and application of Kl allows to renewal their functions by 19-47 %. Under the effect of PCP low doses metabolic processes in caecum of pigs and rabbits also decrease significantly (p < 0,05) and presence of Kl in cultural medium reduces considerably the inhibiting effect of antimicrobial compounds especially where the sources of nutrient substances were more accessible(glucose, RNA, mucin). The cells of saccharolytic bacterium Butyrivibro fibrisolvens 787 metabolize aldoses with different molecular weight with unequal speed. Glucose is utilized 2,5 times faster than xylose. At the presence of both aldoses in growth medium the cells of this strain first utilize glucose and then xylose. Phosphoketolase activity isn't observed on both mentioned monomers in strain cells while lactate dehydrogenase activity in them and in control bacterium-witness (Lactobacillus plantarum 185) is observed on a quite high level. High level of cellular metabolism of B. fibrisolvens is provided by functioning of specific enzymatic reactions which are catalyzed by 2-keto-3-desoxy-6-phosphogluconate aldolase (KDPGA, due to it the metabolic pathway of Entner-Doudoroff is used) and fructosobiphosphate aldolase (FBPA, with the help of which carbohydrates are utilized by the pathway of Embden-Meyerhof-Parnas). The mentioned metabolic pathways are depressed under the influence of even low doses of PCPandthe inhibiting effect of biocide reduces reliably (p < 0,05) at the presence of Kl in the medium.