Colorimetric determination of phytate in unpurified extracts of seeds and the products of their processing

The addition of orthophosphate (up to 20 micrograms/ml of phosphorus) and chlorogenic acid (up to 50 micrograms/ml) does not impair the colorimetric assay of phytate based on the decoloration of Fe3+-sulfosalicylate complex (M. Latta, and M. Eskin (1980) J. Agric. Food Chem. 28, 1313-1315). Phytate was determined in 14 samples of seed meal and protein isolates containing inorganic phosphate and chlorogenic acid. There was no difference between the results of the analysis using crude extracts and those using purified extracts. It is therefore possible to avoid the preliminary purification of extracts as in the original method, thereby simplifying and accelerating the phytate assay to a considerable extent.     

Antiradiation effectiveness of amino acid mixtures of various compositions

Radioprotective efficacy of differently composed amino acid mixtures (e. g. swine brain hydrolyzate, mixtures of several crystalline amino acids, etc.) was estimated. The survival rate and average life of exposed animals increased after the administration of amino acid preparations. The most pronounced effect was produced by the mixtures composed of several crystalline amino acids.     

Spatial distribution and species composition of prosthecate bacteria in Lake Baikal

From the water column of Lake Baikal, several strains of prosthecate bacteria belonging to the genera Caulobacter and Brevundimonas were isolated. In this article, the methods applied for their isolation and cell number determination are described; the occurrence frequency and spatial distribution of these microorganisms in the lake are demonstrated. Characterization of the species composition of cultivable and uncultivable prosthecate bacteria was carried out using the methods of traditional and molecular microbiology, respectively. A comparative phylogenetic analysis of the DNA sequences of uncultivable bacteria, which showed homology to the members of the alpha subclass of proteobacteria, was carried out. It was demonstrated that the lake water column is inhabited by uncultivable alpha-proteobacteria of uncertain phylogenetic affinity, in addition to representatives of the species Caulobacter vibrioides and C. leidyi, which were detected by traditional microbiological methods.     

Comparative effects of limited tryptic hydrolysis on physicochemical and structural features of seed 11S globulins

The effect of the limited proteolysis by trypsin on selected seed storage 11S globulins (broad bean and pea legumins, glycinin and helianthinin) was studied by high-sensitive differential scanning calorimetry, fluorescence spectroscopy and analysis of proteolysis kinetics. Different behaviour of glycinin and helianthinin, on one hand, and broad bean and pea legumins, on the other, were observed: in the first group changes in the physicochemical characteristics of the proteins due to their limited proteolysis are more pronounced in comparison with the second one, in relation with the extent of primary structure modifications. The differences observed have been evaluated in relation with the amino acid sequence features of the four 11S globulin studied and agree with the literature data concerning the protein structural changes in the course of the limited proteolysis.     

Creation of a hard microrelief on a titanium surface processed by microplasma discharges with a current amplitude of 200 A and pulse duration of 20 ms

The interaction of microplasma discharges with samples made of VT1 commercial titanium was studied experimentally. The amplitude of the current pulses of microplasma discharges was 200 A, the pulse duration was 20 ms, and the number of current pulses was from 1 to 10. After microplasma processing, a 10-μm-thick solid remelted surface layer with an increased hardness formed on the titanium samples. As compared to the initial state of titanium samples, the surface layer hardened by microplasma discharges possesses improved parameters: the microhardness increases fivefold, the maximum admissible pressure applied to the samples during friction increases more than 20-fold, the friction wear rate is reduced by three orders of magnitude, and the friction coefficient decreases sixfold.     

The influence that protozoa has on hydrogen sulfide oxidation by phototrophic bacteria

These experiments have been performed with a facility for the simulation of summer stagnation conditions in natural water bodies. Our experimental results suggest that anaerobic ciliates and flagellates can stimulate hydrogen sulfide oxidation and thus the photosynthesis of phototrophic green bacteria in phosphorus deficient media. The phosphorus (as well as nitrogen) limitation of hydrobiological processes is most widespread in natural waters and, therefore, our results may contribute to the understanding of the role that individual organisms and their relationships play in aquatic ecosystems.     

Genotype dependence of cytogenetic and epidemiological characteristics in the liquidators of the accident at the ChNPP

The dependence of the level of unstable chromosome aberrations and nononcological diseases on the genotype in 57 liquidators of the ChNPP accident was studied. Candidate genes presumably affecting radiosensitivity were highly polymorphic loci of xenobiotic detoxication genes (glutathione-S-transferases GSTM1, GSTT1, GSTP1) and the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) involved in DNA methylation and synthesis. An increased frequency (0.014 +/- 0.001 per cell) of unstable chromosome aberrations, including radiation-specific dicentrics and centric rings (0.0015 +/- 0.0002 per cell), has been found to be preserved in the group of liquidators examined in 2006-2007. No associations of polymorphism for each of the studied genes with cytogenetic parameters were revealed. Increased frequencies of chromosome aberrations were recorded in homozygous carriers of a deletion at the GSTM1 locus in combination with homozygosity for minor alleles at the MTHFR and GSTP1 loci (p = 0.00002 and p = 0.0233, respectively). The number of homozygous carriers of the minor allele GSTP1 was increased among patients with chronic obstructive pulmonary disease and in liquidators with acute circulation disturbances (p = 0.014 and p = 0.04, respectively). Double homozygotes for GSTM1 and GSTT1 deletions were significantly more frequent among subjects with benign tumors (cysts, polyps, p = 0.015) and with benign thyroid tumors (p = 0.017). This genotype has proved to be protective for patients with severe cardiovascular diseases (acute circulation disturbances, p = 0.027).