Quantitative isolation of microbial DNA from the different types of soils of natural and agricultural ecosystems

A novel procedure was developed for direct quantitative isolation of microbial DNA from soil. This technique was used to evaluate microbial DNA pools in soils of contrasting types (chernozems and brown forest soils) under different anthropogenic loads. A strong correlation was found between microbial biomass and DNA contents in soils of different types (R2 = 0.799). The ratio of soil CO2 emission rate to the amount of extractable DNA in the soil was shown to reflect physiological state of the soil microbial community; this ratio can be used as an ecophysiological parameter similarly to the metabolic quotient qCO2.     

Influence of neurotensin on behavior of rats with lesions in serotonergic neurons

After serotonergic lesion by administration of 5,7-dihydroxytryptamine into the dorsalis raphe nucleus, effects of neurotensin microinjections into the caudate nucleus and substantia nigra on rat behavior were compared. Serotonergic lesions resulted in motivated excitement of rats manifested as an increase in the number of intersignal motor reactions during realization and, particularly, extinction of thirst conditioned reflex. Neurotensin microinjections into the caudate nucleus facilitated extinction of the conditioned reflex both in operated and control rats, but such microinjection into the substantia nigra facilitated this process only in operated animals. Neurotensin did not change conditioned reflex realization in both groups of animals but decreased emotional excitement of rats in the "open field". The behavioral effects of neurotensin in operated rats are connected with normalization of motivational and emotional states of animals and may be explained by recovery of interaction between the dopamine- and serotonergic systems. It is suggested that the mechanisms of this normalizing effects of neurotensin at the levels of the caudate nucleus and substantia nigra are different and are associated preferentially with its action either on dopamine- or serotonergic structures.     

The role of antioxidant systems in the response of Escherichia coli to acetamidophenol and some antibiotics

The role of glutathione and other antioxidant systems in the response of Escherichia coli to acetamidophenol (paracetamol), rifampicin, and chloramphenicol was studied. The exposure of aerobically growing E. coli cells to acetamidophenol diminished the intracellular level of glutathione by 40% and the reduced-to-oxidized glutathione ratio in the cells by 50%, while it enhanced the expression of the antioxidant genes soxS and sodA by 2.7 and 1.8 times, respectively. Glutathione-deficient cells were more susceptible to acetamidophenol than were normal cells. All this suggests that acetamidophenol induces a mild oxidative stress in E. coli cells. The oxidative stress induced by rifampicin was still less pronounced, whereas chloramphenicol-treated E.coli cells exhibited no signs of oxidative stress at all.     

Russian genofond. Genogeography of surnames

Surnames are traditionally used in population genetics as "quasi-genetic" markers (i.e., analogs of genes) when studying the structure of the gene pool and the factors of its microevolution. In this study, spatial variation of Russian surnames was analyzed with the use of computer-based gene geography. Gene geography of surnames was demonstrated to be promising for population studies on the total Russian gene pool. Frequencies of surnames were studied in 64 sel'sovets (rural communities; a total of 33 thousand persons) of 52 raions (districts) of 22 oblasts (regions) of the European part of Russia. For each of 75 widespread surnames, an electronic map of its frequency was constructed. Summary maps of principal components were drawn based on all maps of individual surnames. The first 5 of 75 principal components accounted for half of the total variance, which indicates high resolving power of surnames. The map of the first principal component exhibits a trend directed from the northwestern to the eastern regions of the area studied. The trend of the second component was directed from the southwestern to the northern regions of the area studied, i.e., it was close to latitudinal. This trend almost coincided with the latitudinal trend of principal components for three sets of data (genetic, anthropological, and dermatoglyphical). Therefore, the latitudinal trend may be considered the main direction of variation of the Russian gene pool. The similarity between the main scenarios for the genetic and quasi-genetic markers demonstrates the effectiveness of the use of surnames for analysis of the Russian gene pool. In view of the dispute between R. Sokal and L.L. Cavalli-Sforza about the effects of false correlations, the maps of principal components of Russian surnames were constructed by two methods: through analysis of maps and through direct analysis of original data on the frequencies of surnames. An almost complete coincidence of these maps (correlation coefficient rho = 0.96) indicates that, taking into account the reliability of the data, the resultant maps of principal components have no errors of false correlations.     

Determination of the parameters for producing a biobinder from wood: a mathematical modeling of the transformation of lignocellulose substrate by the fungus Panus tigrinus

A biochemical scheme for the transformation of wood lignocellulose during enzymatic hydrolysis of polysaccharides and lignin destruction in reactions involving free radicals was developed, and a corresponding mathematical model was constructed. Processing (fermentation) of wood particles by the fungus Panus tigrinus in a submerged culture for producing a biobinder of wood composites--woodchip boards and fiber-boards--is considered. The mathematical model was used to study the technological parameters that influence the production of enzymes and fungal biomass and the level of free radical accumulation in the substrate, i.e., the factors determining the production of the biobinder. The optimal values of these parameters were determined, namely: the specific surface of wood particles, amounting to 2000 cm2/g; processing time of 56 h; and an initial concentration of 3.0 g/l of fungal biomass in the submerged culture.     

Profiles of the utilization of 20 amino acids as the only source of nitrogen and carbon in bacteria of the genera Klebsiella, Enterobacter, Serratia, Escherichia

The profiles of the utilization of 20 protein amino acids in 118 Klebsiella pneumoniae sub- sp. pneumoniae, K. oxytoca, K. planticola, K. mobilis, Enterobacter cloacae, Serratia marscescens, S. liquefaciens, Escherichia coli strains isolated from clinical material were studied. The utilization of amino acids was determined on minimal saline agar containing amino acid as the only source of nitrogen and carbon; the results were evaluated after 72-hour incubation at 37 degrees C. 17 profiles of amino-acid utilization were thus determined, most of them genus-specific in enterobacteria: Klebsiella (profiles No. 1--6, 9, 10), Enterobacter (No. 11--13), Serratia (No. 14--16), Escherichia (No. 17). The full coincidence of amino-acid utilization profiles in bacteria of K. mobilis (No. 1, 6) and K. pneumoniae subsp. pneumoniae with out of such profiles in bacteria of the genera Enterobacter, Serratia, Escherichia was established, which confirmed that K. mobilis (formerly Enterobacter aerogenes) belonged to the genus Klebsiella.     

Identification of Ca(2+)-activated Mg(2+)-dependent ATP-hydrolase activity of membrane microsomal fraction of loach embryo (Misgurnus fossilis L.)

The functional confirmation of availability of Ca2+ transport initially-active systems in the embryo cells of loach Misgurnus fossilis L. has been obtained. Using thapsigargin, the specific inhibitor of endoplasmic reticulum of Ca2+, Mg(2+)-ATPase, this enzyme activity was divided into thapsigargin-sensitive (actually endoplasmic reticulum Ca2+, Mg(2+)-ATPase) and thapsigargin-insensitive (plasma membrane Ca2+, Mg(2+)-ATPase) constituents. The Ca(2+)-independent Mg(2+)-dependent ATPase activity makes above 39.7% of the common Ca2+, Mg(2+)-ATPase activity of embryo loach. The periodic changes of Ca2+, Mg(2+)-ATPase activity (except for the changes of plasma membrane Ca2+, Mg(2+)-ATPase activity) were found out, which coincide with periodic [Ca2+]i oscillations during the synchronous divisions of loach blastomers embryos.