Trade in the Decade Following the Collapse of the USSR

In Soviet times, Moscow was a consumers’ oasis in a country of rampant scarcity. Millions of workers and peasants from all the free republics met in the capital of the unbreakable Union to stock up on delicacies, foreign goods, and all the things not available in the national hinterland. As new markets with a certain degree of specialization emerged, this introduced more stringent terms of trade and other measures aimed at eliminating the negative impact of commerce on the environment and improving the sanitary condition of the area, as well as improving traffic conditions and the general appearance of the environment. The authors analyze the space of commerce during the Soviet Union’s existence and after its collapse, and show how popular attitudes changed.     

Comparison of the adaptive potential of the Arthrobacter oxydans and Acinetobacter lwoffii isolates from permafrost sedimentary rock and the analogous collection strains

A comparative study was conducted on the adaptive mechanisms of the strains Arthrobacter oxydans K14 and Acinetobacter lwoffii EK30A isolated from permafrost subsoil sediments and of those of the analogous collection strains (Ac-1114 Type and BSW-27, respectively). In each pair of the strains compared, the strains differed in terms of (i) growth-related, physiological, and biochemical properties; (ii) resistance to stress factors; (iii) capacity for generation of dormant forms (DFs) under growth arrest conditions, and (iv) intrapopulation production of phase variants. The strains isolated from permafrost displayed a lower growth rate but were more resistant to repeated freezing-thawing treatment than the collection strains. Under the same growth conditions, the permafrost strains formed larger numbers of cystlike anabiotic DFs, extraordinarily small cells, and forms that became nonculturable during long-term storage. Resuscitation of the nonculturable forms resulted in a 2- to-7-fold increase in the percentage of FISH-detectable metabolically active cells. The permafrost strains were also distinguished by increased genome lability. This facilitated their dissociation into intrapopulation variants with phenotypically distinct colonial and morphological properties and different antibiotic resistance. The phenotypic variability was more prominent in Arthrobacter (for which it was not reported previously) than in Acinetobacter. In the populations produced by plating the dormant bacterial forms, the qualitative and quantitative characteristics of the phase variant spectra varied depending on the formation conditions and the composition of the solid media used for the plating. Thus, the permafrost isolates of A. oxydans and Ac. lwoffii were distinguished from their collection analogs by a more manifest adaptive potential including stress resistance, the intensity of DF generation under growth arrest conditions, and increased intrapopulation variability.     

Effect of the reactivating factor of Luteococcus japonicus subsp. casei on the expression of SOS response genes

The effect of the extracellular peptide reactivating factor (RF) synthesized by Luteococcus casei on stress response of Escherichia coli cells subjected to UV irradiation was studied. For these studies, we constructed a test strain carrying the umuD-lacZ operon. The expression rate of this operon reflects the rate of SOS response. Protective effect of RF, defined as the number of cells retaining the colony-forming activity (CFU) after UV irradiation (49–1166 J/m²), was dose-dependent, species-nonspecific, and increasing with increase of the stress load. RF was demonstrated to possess the properties of a direct adaptogen: 15 min of preincubation with RF caused a 1.5–6-fold decrease in expression of the umuD SOS response gene in UV-treated cells, concurrently with a 1.2–7.5 times increase in the number of viable cells (those having retained their colony-forming activity). The probable mechanisms of the protective effect of RF are being discussed.     

Disaggregation of Platelet Aggregates Formed by the Action of Thrombin in the Presence of Hydrogen Peroxide

The aggregation and change in the intracellular Ca2+ concentration induced by thrombin (0.005-0.22 U/ml) in the presence of H2O2 (0.05-0.6 mM) was investigated. Under the chosen experimental conditions (incubation time of platelets with H2O2 not more than 15 sec), H2O2 neither accelerated nor inhibited the thrombin-induced platelet aggregation. However, platelet aggregates formed by the action of thrombin in the presence of H2O2 were unstable and disaggregated. Disaggregation was abolished by catalase added after thrombin. The disaggregation effect was dose-dependent; the process of disaggregation was confirmed by electron microscopy. Hydrogen peroxide did not influence thrombin-induced increase in the intracellular Ca2+ concentration, but dose-dependently accelerated Ca2+ extrusion from the platelet cytoplasm.     

Changes in physicochemical properties of proteins, caused by modification with alkylhydroxybenzenes

Kinetic characteristics of model enzymes and physicochemical properties of globular proteins modified by chemical analogues of low-molecular-weight microbial autoregulators (alkylhydroxybenzenes, AHBs) have been studied. C₇ and C₁₂ AHB homologues were used, differing in the length of the alkyl radical and the capacity for weak physicochemical interactions. Both homologues affected the degree of protein swelling, viscosity, and the degree of hydrophobicity. The effects depended on the structure of AHBs, their concentration, and pH of the solution, which likely reflects changes in the charge of the protein globule and its solvate cover. Variations of hydrophobicity indices of AHB-modified enzymes (trypsin and lysozyme) were coupled to changes in the catalytic activity. The values of K _M, measured for the enzymes within both AHB complexes, did not change, whereas V _max increased (in the case of C₇ complexes) or decreased (C₁₂ complexes). Possible molecular mechanisms of changes in the physicochemical and catalytic parameters of enzymatically active proteins, induced by modification with structurally distinct AHBs, are described, with emphasis on targeted regulation of functional activity.     

H2O2-Induced Platelet Aggregation and Increase in Intracellular Ca2+ Concentration Are Blocked by Inhibitors of Intracellular Signaling

Inhibitors of signaling enzymes such as guanosine-5-O-2-thiodiphosphate, aristolochic acid, aspirin, indomethacin, and trifluoperazine block H₂O₂-induced platelet aggregation and H₂O₂-induced increase in the intracellular concentration of Ca²⁺. These findings suggest that the effect of H₂O₂ on platelets is associated with activation of signal pathways responsible for increase in the concentration of intracellular Ca²⁺. On H₂O₂-induced platelet aggregation, the concentration of cAMP in the cytoplasm decreases and that of cGMP increases.     

The role of microbial dormancy autoinducers in metabolism blockade

Alkyl-substituted hydroxybenzenes (AHBs), which are autoinducers of microbial dormancy (d ₁ factors), were found to stabilize the structure of protein macromolecules and modify the catalytic activity of enzymes. In vitro experiments showed that C₆-AHB at concentrations from 10⁻⁴ to 10⁻² M, at which it occurs in the medium as a true solution and a micellar colloid, respectively, nonspecifically inhibited the activity of chymotrypsin, RNase, invertase, and glucose oxidase. C⁶-AHB-induced conformational alterations in protein macromolecules were due to the formation of complexes, as evidenced by differences in the fluorescence spectra of individual RNase and C₆-AHB and their mixtures and in the surface tension isotherms of C₆-AHB and trypsin solutions. Data on the involvement of dormancy autoinducers in the posttranslational modification of enzymes and their inhibition will provide further insight into the mechanisms of development and maintenance of dormant microbial forms.     

Low-Molecular-Weight Autoregulatory Factors in the Haloalkaliphilic Bacteria Thioalkalivibrio versutus and Thioalkalimicrobium aerophilum

The haloalkaliphilic, lithoautotrophic, sulfur-oxidizing gram-negative bacteria Thioalkalivibrio versutus and Thioalkalimicrobium aerophilum were found to possess a special system for the autoregulation of their growth. The system includes the extracellular autoinducers of anabiosis (the d₁ factor) and autolysis (the d₂ factor). The principal components of the d₁ factor are alkylhydroxybenzenes, as evidenced by specific qualitative reactions. The principal components of the d₂ factor are free unsaturated fatty acids dominated by oleic acid isomers. Like the respective autoregulators of neutrophilic bacteria, the d₁ factor of haloalkaliphilic bacteria presumably controls their growth and transition to anabiotic state, while the d₂ factor controls autolytic processes. Alkylhydroxybenzenes of both microbial and chemical origin were found to influence bacterial respiration. The low-molecular-weight osmoprotectant glycine betaine enhanced the thermostability of trypsin. This suggests that both glycine betaine and the d₁ factor serve as chemical chaperones.