Microbial communities of ancient seeds derived from permanently frozen Pleistocene deposits

Microbial communities from the surface of ancient seeds of higher plants and embedding frozen material dated to the late Pleistocene (formed about 30 thousand years ago) were studied by various methods: scanning electron microscopy, epifluorescence microscopy, and inoculation of nutrient media, followed by identification of isolated cultures. Both prokaryotic and eukaryotic microorganisms were found on the surface of ancient seeds. The total quantity of bacterial cells determined by direct counting and dilution plating (CFU) for the samples of ancient seeds exceeded the value in the embedding frozen material by one to two orders of magnitude. This pattern was not maintained for mycelial fungi; their quantity in the embedding material was also rather high. A significant difference was revealed between the microbial communities of ancient seeds and embedding frozen material. These findings suggest that ancient plant seeds are a particular ecological niche for microorganisms existing in permafrost and require individual detailed study.     

Integration of human plasminogen or streptokinase into stable complexes with oxidoreductases and pyruvate kinase

Summary The formation of stable equimolar complexes of streptokinase or plasminogen with muscle lactate dehydrogenase or pyruvate kinase, heart mitochondrial malate dehydrogenase and hepatic catalase at pH 7.4, 3.0 and 10.0 was first detected by differential spectroscopy methods. All complexes, except those of plasminogen with dehydrogenases, were resistant to 6 M urea. Judging from circular dichroism spectra, tertiary and secondary structures were considerably changed in the complexes. These changes were significantly dependent upon the nature of interacting proteins; in some cases their structures were more ordered. NAD (but not NADH) hampered the formation of streptokinase complexes with dehydrogenases. The plasminogen-activating function of streptokinase and the ability of plasminogen to be activated by streptokinase in the complexes with oxidoreductases were essentially unchanged. Pyruvate kinase induced a moderate (by 35%) increase in the streptokinase activating function. It is assumed that the formation of complexes of streptokinase or plasminogen with enzymes may serve as a link in metabolic regulation and/or intercellular interactions.     

Microbial Communities of Soils and Soil-like Bodies in Extreme Conditions of East Antarctica

Paleontological Journal - Results of an integrated study of microbial communities in soils and soil-like bodies formed in the wet intermountain valleys of East Antarctic oases under moss-, lichen-,...     

Diversity of Borrelia burgdorferi sensu lato in Russian Far East

Thirty strains of Borrelia burgdorferi sensu lato have been isolated from Ixodes persulcatus ticks and from skin lesions of Lyme disease patients in the Russian Far East from 1997 to 2003. We amplified full-length outer surface protein A (ospA) gene of all strains. BLAST search and following phylogenetic analysis showed that strains form four well-defined groups. Four strains belong to Borrelia afzelii species. Other strains distributed into tree major groups, identified as Borrelia garinii. Indeed, based on the ospA gene comparison, phylogenetic relationship of these groups among each other does not differ from relationship among other previously defined groups inside B. burgdorferi sensu lato genogroup, such as B. afzelii or Borrelia bissettii. Further investigations of genetic and serologic properties of the strains belonging to those groups are required in order to clarify their taxonomic status.     

Extension of life span of Drosophila melanogaster by the inhibitors of tryptophan-kynurenine metabolism

Upregulation of kynurenine (KYN) formation from tryptophan (TRY) was associated with aging in animal and human studies. TRY-KYN metabolism is affected by the activities of TRY 2,3-dioxygenase 2 (TDO) and AT P-binding cassette (ABC) transporter regulating TRY access to intracellular TDO. We studied the effects of TDO inhibitor, alpha-methyl tryptophan (aMT) and ABC transported inhibitor, 5-methyl tryptophan (5MT), on the life span of wild strain female Drosophila flies (Oregon-R). aMT and 5MT prolonged mean and maximum life span (by 27% and 43%, and 21% and 23%, resp.). The present results are the first observation of the extension of life span of Drosophila melanogaster by inhibitors of TRY-KYN metabolism, and in line with literature and previous studies on prolonged life span of TDO- and ABC-deficient female Drosophila mutants. Inhibition of TDO and ABC transporter activity might offer the new target for anti-aging interventions.     

Genetic analysis of the contributions of individual chromosomes to the expression of mating behavior traits in Drosophila melanogaster

The model of isogenous strains with chromosome substitutions has been used to estimate the relative contributions of the X chromosome and autosomes (chromosomes 2 and 3) to the control of some mating behavior traits in Drosophila melanogaster. It has been found that the male sexual activity (SA), female sexual receptivity (SR), and copulation latency (CL) are determined by interaction between X-chromosome and autosomal genes, whereas the copulation duration (CD) is mainly controlled by the X-chromosome genes. The synthesized isogenous strains have been shown to be more similar to hybrids than to the original strains. In the offspring with hybrid genotypes, the relationships between all traits are less stable, which may be related with an increase in the heterozygosity level and changes in genetic homeostasis.     

The effect of volatile antioxidants of plant origin on leukemogenesis in mice

The effect of savory essential oil added with drinking water (150 ng/ml) or with feed (2.5 μg/g) on the lifetime of AKR mice and the parameters of oxidative stress in animal blood were investigated. It was found for the first time that long-term administration of an essential oil in low doses increased the average lifetime of mice by 20–35% and was accompanied by a decrease in the hemolysis level and the content of lipid peroxidation products in erythrocytes of mice, as well as alteration in the structural state of their membranes and stabilization of polyunsaturated fatty acids level in mice liver cells.     

Cytogerontological studies of biological activity of oregano essential oil

In order to clarify possible cytological mechanisms that underlie the beneficial effects of carvacrol-bearing essential oils on health and mental abilities, we studied one of them (oregano essential oil) in experiments on transformed cultured Chinese hamster cells. Possible cytotoxic or mitogenic effects of the preparation at various concentrations were preliminarily estimated by analyzing the cell culture density after 4 days of cultivation. The preparation concentration in the growth medium (on carvacrol basis) varied from 1 × 10^?15 up to 5 × 10^?4 M (on carvacrol basis). As a result, two concentrations were selected for further experiments, including 2.5 × 10^?5 M as the maximal absolutely non-toxic concentration and 2.5 × 10^?4 M as the concentration at which the oregano essential oil decreased approximately 2-fold the final cell density of the grown culture. It was found that the preparation at 2.5 × 10^?5 M had no effect on either the colony-forming ability of the cells or the saturation density of the culture (which is a marker of its ??biological age??) or kinetics of its ??stationary phase aging?? (degradation of cultured cells in the stationary phase of growth, similar to age-related changes of the cells in aging organism). On the contrary, the oregano essential oil at 2.5 × 10^?4 M abruptly diminished colony-forming ability of the cells and influenced as a ??pro-aging?? factor on the saturation density of the cell culture and kinetics of the cell death induced by ??stationary phase aging.?? Based on our own concept of aging and the data obtained, we assumed that detected increase in the life span of mice under the influence of the oregano essential oil could be determined by certain functional changes at the organismal level only, but is not associated with any geroprotective (anti-aging) activity of the preparation, which is manifested at the cellular level and improves the cell viability.