[Biological activity of probiotic microorganisms].

Adaptation of bifidobacteria and lactic acid bacteria to nutrient media with increased concentrations of bile (1%) and protein substrates of animal origin allowed the variants resistant to bile and displaying a high production of proteolytic enzymes (active within the pH range of 2.5-9.0) to be selected. Administration of the preparations involving the selected bifidobacteria and lactic acid bacteria assisted in the normalization of the intestinal microflora and activation of protein metabolism in the organism of animals. Specifically, it increased the total protein level in blood serum and redistributed protein fractions, increasing the content of globulins and decreasing albumin concentration.

[Study of the physiological and biochemical characteristics of bifidobacteria at the late stages of population development]. / Issledovanie fisiologo-biokhimicheskikh osobennostei bifidobakterii na pozdnikh stadiiakh razvitiia populiatsii.

An investigation of the physiological and biochemical characteristics of the Bifidobacterium bifidum no. 1, B. adolescentis MC-42, and B. adolescentis 94-BIM strains showed that bifidobacteria with a higher growth rate produced greater amounts of the end fermentation products, acetate and lactate. The growth of the strains in batch cultures was found to be inhibited by acidic fermentation products. The growth of B. bifidum no. 1 in a batch mode lasted 100 h at a population density of 10(6) CFU/ml and the growth of B. adolescentis MC-42 and 94-BIM lasted 96-120 h at population densities from 10(4) to 10(7) CFU/ml. Analysis of the bifidobacterial populations by light and electron microscopy showed that they represent conglomerates of cells with lysed cytoplasm in the cell center and intact cytoplasm in the apical parts of the cells. The maximum production of extra-cellular and cell-bound proteinases was observed in the logarithmic growth phase. By the 120th h of cultivation, the metabolic activity of cells, the production of proteinases, and the protein content of bifidobacterial cultures considerably decreased. In the first, second, and third subcultures of 96-h-old bifidobacterial cells on fresh nutrient media, the population density of bifidobacteria and their normal physiological and biochemical characteristics were restored after 48 to 72 h of cultivation.

[Microelements preparations obtained during processing of natural flint affect the physiology and biochemistry of bifidobacteria]. / Vliianie preparatov mikroélementov, poluchennykh pri obrabotke prirodnogo minerala kremnia, na fiziologo-biokhimicheskie osobennosti biofidobakterii.

Microelement preparations obtained in the course of processing of flint powder stimulate the biological activity of Bifidobacterium adolescentis 94 BIM, grown on complex and synthetic nutritive media. The composition of the microelement preparations differed in the content of cations and anions. Introduction of the preparations into the cultures of physiologically active or anabiotic forms of bifidobacteria changed the parameters of exponential growth: compared to controls, the cultures were characterized by increased specific growth rate and decreased generation time. In the presence of microelements, the development of populations of bifidobacteria was associated with more pronounced accumulation of metabolic products (acetate, lactate, and ethanol). Introduction of microelement preparations increased the rate of synthesis of the extracellular proteinase (maximum content of the enzyme was observed after 3 h, whereas control cultures attained this level only after 6 h).

[Production of proteinases associated with Bifidobacterium adolescentis 94-BIM cell wall]. / Produktsiia assotsiirovannykh s kletochnoi stenkoi proteinaz Bifidobacterium adolescentis 94-BIM.

Bifidobacterium adolescentis 94-BIM was found to produce cell-wall bound proteolytic enzymes active at acidic, neutral, and alkaline pH values. The solubilization of proteinases with 0.5% Triton X-100 substantially improved the yield of the enzymes. The most active accumulation of cell-bound proteinases was observed in the third hour of cultivation at rates of 156.7, 179.5, and 111.1 U/(mg h), measured at pH 2.5, 7.0, and 9.0, respectively. It is suggested that the cell-wall bound proteinases of B. adolescentis 94-BIM are the precursors of the enzymes secreted into the medium.

[Isolation and characteristics of a protein-polysaccharide complex, secreted by Bifidobacterium adolescentis]. / Vydelenie i kharakteristika belkovo-polisakharidnogo kompleksa, sekretiruemogo Bifidobacterium adolescentis.

Extracellular fibrillar protein-polysaccharide complex (PPC) of Bifidobacterium adolescentis was found to be bound to the outer surface of the cell wall. However, at the late stages of B. adolescentis cultivation (48-72 h of growth), it also occurred in the culture liquid, which can be explained by the expansion of the outer material of the cell wall. PPCs isolated from the cell surface and culture liquid contained proteins and carbohydrates in a ratio of 1:1 and from 1:4 to 1:5, respectively. PPC exerted a concentration-dependent bifidogenic effect: it stimulated growth, acidogenesis, accumulation of extracellular proteins and enzymes, and sugar utilization in B. adolescentis cells grown in synthetic Eagle's medium. PPC also promoted the rehabilitation of anabiotic forms of B. adolescentis. The PPC variants III-DN-48 and IV-DN-24, isolated from the cell surface of B. adolescentis, had the most pronounced bifidogenic effect.

[Features of growth and formation of extracellular proteinases of Bifidobacterium adolescentis 94-BIM]. / Osobennosti rosta i obrazovaniia vnekletochnykh proteinaz Bifidobacterium adolescentis 94-BIM.

Growth characteristics of a new bifidobacterial strain, Bifidobacterium adolescentis 94-BIM, were determined during cultivation in various nutrient media. The strain was obtained through selection by the criterion of proteolytic activity and was shown to synthesize acidic, neutral, and alkaline extracellular proteinases in all of the growth media tested. The growth yield of the strain varied from 2.9 x 10(8) to 1.7 x 10(10) CFU/ml with acidogenesis of up to 131 degrees T. The most rapid growth and accumulation of extracellular proteinases were observed during the first 24 h of cultivation. The maximum growth rate (0.144 h-1) was observed in the ninth hour of cultivation, whereas the most rapid accumulation of acidic, neutral, and alkaline proteinases (at rates of 53, 88.8, and 59.2 units/(mg h), respectively) occurred in the sixth hour of cultivation.