The Content of Vitamin C in the Grape Grown under the Conditions of Southwestern Siberia

Russian Journal of Bioorganic Chemistry - The grape is a highly valuable food stuff owing to the presence of a number of biologically active substances, and vitamins occupy a special place among...     

Results of testing the comparatory method: The curvature of the shell valve frontal section is inappropriate as a systematic character for the freshwater pearl mussel of the genus Margaritifera

This paper continues a discussion on the number of pearl mussel species of the genus Margaritifera in northern Europe. A biometric study of 1711 pearl mussel Margaritifera margaritifera shells from 15 rivers in Russia and Latvia (basins of the White and Baltic seas) has been conducted. All the examined samples fall into two groups: the northern group (with the shells more flattened on average, f. margaritifera) and the southern one (with more convex shells, f. elongata); the boundary between these groups is at 63° N. Analysis of intrapopulation variation has shown that the samples contain individuals that correspond to f. margaritifera, f. elongata, and f. borealis. However, any hiatus between these forms is absent in all the samples, and individuals belonging to two intermediate forms are rather frequent. The hypothesis on the species specificity of the shell valve frontal section has not been confirmed based on examination of large shell samples. The pearl mussels inhabiting rivers of Northern Europe belong to a single species, M. margaritifera.     

Ortho-phthalic acid esters in lipophilic extract from the cell culture of <Emphasis Type="Italic">Aconitum baicalense</Emphasis> Turcz ex Rapaics 1907

Optically active bis-2R(–)ethylhexyl o-phthalate was obtained with 0.18% yield from dry cultured cells of Aconitum baicalense Turcz ex Rapaics 1907 by extraction with petroleum ether followed by silica gel column chromatography. Its structure was confirmed by the analysis of ¹³C and ¹H NMR spectra. Seasonal fluctuations of quantitative phthalate content in A. baicalense cells were identified. The tests were performed under conditions excluding the presence of phthalates in reagents, materials, and laboratory dishes. The same substance was shown to be produced by cultivated cells of other plants. Biosynthesis of esters of ortho-phthalic acid by cultivated plant cells was discovered for the first time.     

Hydrocarbon biodegradation and surfactant production by acidophilic mycobacteria

Production of biosurfactants by acidophilic mycobacteria was demonstrated in the course of aerobic degradation of hydrocarbons (n-tridecane, n-tricosane, n-hexacosane, model mixtures of С₁₄–С₁₇, С₁₂?С₁₉, and С₉–С₂₁n-alkanes, 2,2,4,4,6,8,8-heptamethylnonane, squalane, and butylcyclohexane) and their complex mixtures (hydrocarbon gas condensate, kerosene, black oil, and paraffin oil) under extremely acidic conditions (pH 2.5). When grown on hydrocarbons, the studied bacterial culture AG_S10 caused a decrease in the surface and interfacial tension of the solutions (to the lowest observed values of 26.0 and 1.3 mN/m, respectively) compared to the bacteria-free control. The rheological characteristics of the culture changed only when mycobacteria were grown on hydrocarbons. Neither the medium nor the cell-free culture liquid had the surfactant activity, which indicated formation of an endotype biosurfactant by mycobacteria. Biodegradation of n-alkanes was accompanied by an increase in cell numbers, surfactant production, and changes in the hydrophobicity of bacterial cell surface and in associated phenomena of adsorption and desorption to the hydrocarbon phase. Research on AGS10 culture liquids containing the raw biosurfactant demonstrated the preservation of its activity within a broad range of pH, temperature, and salinity.     

Epigenetic mechanisms regulating seed germination rate

Changes in epigenetic polymorphism degree within wheat seedlings’ population under radiation stimulating exposure of germination were investigated. Variations in seeds sample allocations by germination rate in both control and chronically exposed variants were estimated. Changes in DNA methylation patterns of seedlings from seeds with different germination rate were studied. Variations in epigenetic polymorphism–“distance” between DNA methylation patterns of “fast” and “slow” seedlings of different wheat varieties under radiation exposure were assessed. Indicated, that increased germination rate of seeds sample was associated with decreasing degree of epigenetic polymorphism. Issue concerning both role of epigenetic polymorphism in plant population stability and its decreasing degree that could initiate less effectiveness of production process was discussed.     

Effect of partial hepatectomy on the invertor mechanism of regulation of the Na+,K+-ATPase activity in hepatocytes of rats of various ages]

Age peculiarities of partial hepatectomy effect on the hepatocytes plasma membrane Na+, K(+)-ATPase activity and its insulin-induced stimulation has been studied. It has been shown that partial hepatectomy does not change basal Na+, K(+)-ATPase activity in adult rats. In old partial hepatectomised rats Na+, K(+)-ATPase activity is slightly higher than in control old rats, although this increase is not statistically significant. At the same time, partial hepatectomy acts differently on the insulin-induced Na+, K(+)-ATPase activation in adult and old rats. Insulin activates Na+, K(+)-ATPase at the same extent both in control and partial hepatectomized adult animals. In old hepatectomized rats, but not in old control animals, insulin stimulates Na+, K(+)-ATPase activity as well as. Thus hepatectomy "rejuvenates" old hepatocytes and results in recovery of invertor mechanism of Na+, K(+)-ATPase activation.     

Phylogenetic diversity of aerobic saprotrophic bacteria isolated from the Daqing oil field

A diverse and active microbial community in the stratal waters of the Daqing oil field (China), which is exploited with the use of water-flooding, was found to contain aerobic chemoheterotrophic bacteria (including hydrocarbon-oxidizing ones) and anaerobic fermentative, sulfate-reducing, and methanogenic bacteria. The aerobic bacteria were most abundant in the near-bottom zones of injection wells. Twenty pure cultures of aerobic saprotrophic bacteria were isolated from the stratal waters. Under laboratory conditions, they grew at temperatures, pH, and salinity values typical of the stratal water from which they were isolated. These isolates were found to be able to utilize crude oil and a wide range of hydrocarbons, fatty acids, and alcohols. Phylogenetic analysis carried out with the use of complete 16S rRNA sequences showed that the isolates could be divided into three major groups: gram-positive bacteria with a high and a low G + C content of DNA and gram-negative bacteria of the gamma-subclass of the Proteobacteria. Gram-positive isolates belonged to the genera Bacillus, Brevibacillus, Rhodococcus, Dietzia, Kocuria, Gordonia, Cellulomonas, and Clavibacter. Gram-negative isolates belonged to the genera Pseudomonas and Acinetobacter. In their 16S rRNA sequences, many isolates were similar to the known microbial species and some probably represented new species.     

Optimization of cultivation medium for the production of Bacillus intermedius 3-19 glutamyl endopeptidase

The effect of some components of cultivation medium on the growth of the streptomycin-resistant Bacillus intermedius strain 3-19 and on the production of glutamyl endopeptidase was investigated using factorial experimental design, which allowed the concentrations of peptone and inorganic phosphate to be optimized for the maximum production of the enzyme. Experiments with different peptones and casamino acids showed that the enzyme production is maximum with peptone 3 of plant origin. The addition of casamino acids or amino acids to the peptone-containing cultivation medium inhibited the production of glutamyl endopeptidase.     

Effect of antenatal and postnatal hypoxia on the central nervous system and its correction with peptide hormones

Ante- and postnatal acute hypoxia significantly aggravated the postnatal development. The posthypoxic behaviour patterns included hyperactivity and training ability inhibition typical for the attention deficit syndrome. A preventive injection of peptide constellation significantly improved the posthypoxic postnatal development and abolished the most of the negative modifications of behavioural patterns.