Biological activities of human interferon and 2′–5′ oligoadenylates in plants

Exogenous human interferon 2 (IFN) and 2–5 oligoadenylates (2–5A) have been shown to cause at least a dual physiological effect in tobacco and wheat: (i) increased cytokinin activity and (ii) induced synthesis of numerous proteins, among which members of two groups of stress proteins have been identified, namely pathogenesis-related (PR) and heat shock (HS) proteins. These effects were observed only by low concentrations of these substances: IFN at 0.1–1 u/ml and 2–5A at 1–10 nM.     

Effect of the Medium Composition and Cultivation Conditions on Sporulation in Chemolithotrophic Bacteria

The possibility of regulating endospore formation by changing cultivation conditions was for the first time shown in acidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans type strain 1269 and the thermotolerant strain K1 formerly described as S. thermosulfidooxidans subsp. thermotolerans. Suppression of sporulation occurred when these strains were cultured in Manning's liquid medium with yeast extract. This medium was optimized by gradually reducing the concentrations of ferrous iron salts (the source of energy), phosphorous, nitrogen, and yeast extract and simultaneously increasing the concentrations of calcium, magnesium, and manganese (the elements important for sporogenesis) to attain higher yields of endospores by strains 1269 and K1. As a result, a new medium A was proposed, in which, under aeration, the life cycle of the strains studied culminated in sporulation at a level of 45 and 60%, respectively, of the total cell number. In a series of additional tests, the growth temperature and medium pH were adjusted to obtain the maximum yield of endospores. The optimal ranges found were 40–50°C and pH 1.8–2.2 for strain 1269 and 35–40°C and pH 2.5–2.7 for strain K1. An even higher yield of endospores, amounting to 55 and 75% for strains 1269 and K1, respectively, was obtained when the above growth conditions were combined (growth on medium A at optimal temperatures and pH under static conditions). Our results suggest a new approach to optimizing sporulation by acidophilic chemolithotrophs, which consists in limiting the energy and nutrient sources and using temperature and pH values within the tolerance bounds of these cultures but outside their growth optimum ranges.     

Activity of the Enzymes of Carbon Metabolism in Sulfobacillus sibiricus under Various Conditions of Cultivation

The thermoacidophilic iron-oxidizing chemolithotroph Sulfobacillus sibiricus N1^T is characterized by steady growth and amplified cell yield when grown in vigorously aerated medium containing Fe²⁺, glucose, and yeast extract as energy sources. In this case, carbon dioxide, glucose, and yeast extract are used as carbon sources. Glucose is assimilated through the fructose-bisphosphate pathway and the pentose-phosphate pathway. The glyoxylate bypass does not function in S. sibiricus, and the tricarboxylic acid cycle is disrupted at the level of 2-oxoglutarate dehydrogenase. The presence of ribulose-bisphosphate carboxylase indicates that carbon dioxide fixation proceeds through the Calvin cycle. The activity of ribulose-bisphosphate carboxylase is highest in autotrophically grown cells. The cells also contain pyruvate carboxylase, phosphoenolpyruvate carboxylase, phosphoenolpyruvate carboxykinase, and phosphoenolpyruvate carboxytransphosphorylase.     

Chemical and microbiological solubilization of silicates

The solubilization of silicates was investigated using kaolin and quartz sand as model substances. The mineral solubilization was studied in the concentration of solubilized Si and Al. The chemical leaching of the silicates was carried out using inorganic and organic acids as well as sodium hydroxide. The process was more effective in the alkine than in the acid pH range. In the acid medium, oxalic acid showed maximum acidity and a tendency to form complex structures, especially with aluminium, and was most effective in leaching. The microbiological influence on solubilization reactions was tested using a number of microorganisms among them acid, alkali and slime-forming species. The highest leaching activity was observed in the case of Thiobacillus thiooxidans, whereas the heterotrophic microorganisms (among them Bacillus mucilaginosus) did not exercise a sollubilizing effect on the silicates. X-ray phase analysis of leached kaolin samples did not show any differences from the non-leached mineral.     

The antidepressant-like effect of Ocimum basilicum in an animal model of depression

We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.     

Leaching of copper ore of the Udokanskoe deposit at low temperatures by an association of acidophilic chemolithotrophic microorganisms

Pure cultures of indigenous microorganisms Acidithiobacillus ferrooxidans strain TFUd, Leptospirillum ferrooxidans strain LUd, and Sulfobacillus thermotolerans strain SUd have been isolated from the oxidation zone of sulfide copper ore of the Udokanskoe deposit. Regimes of bacterial-chemical leaching of ore have been studied over a temperature range from −10 to +20°C. Effects of pH, temperature, and the presence of microorganisms on the extraction of copper have been shown. Bacterial leaching has been detected only at positive values of temperature, and has been much more active at +20 than at +4°C. The process of leaching was more active when the ore contained more hydrophilic and oxidized minerals. The possibility of copper ore leaching of the Udokanskoe deposit using sulfuric acid with pH 0.4 at negative values of temperature and applying acidophilic chemolithotrophic microorganisms at positive values of temperature and low pH values was shown.     

Removal of Nonferrous Heavy Metals from Industrial Sewage Using Biosorbents

Producers of the antibiotics neomycin and lincomycin were most potent in sorbing nonferrous metals; they removed 99% Zn and Cd and 95% Ni. The degree of metal sorption increased with an increase in solution pH and calcium content in the biomass. Dynamic studies of biosorbents prepared from a microbial biomass showed that neomycin industrial waste products are highly efficient in treating galvanic washing water. The total dynamic exchange capacities by nickel and cadmium were 6.85 and 7.16 mg/ml, respectively.     

Ultrastructural organization of Alicyclobacillus tolerans strain K1T cells

Electron microscopy examinations of thin sections and freeze-fracture replicas revealed the specific ultrastructural features of Alicyclobacillus tolerans strain K1(T). In particular, the cell wall displayed an ultrastructure typical of gram-positive bacteria and consisted of a thin murein layer (50-60 A in thickness); cells exhibited a surface S-layer constituted by large hexagonally packed (p6-symmetry) rod-shaped subunits of 150-160 A in diameter and 200 A in height. In the cytoplasmic membrane, there were intramembrane vesicular structures that sometimes appeared as large leaflets in the central part. The cytoplasm contained numerous vesicular inclusions covered with a monolayered wall, dissimilar to bilamellar lipid membranes. Endospore coats displayed an intricate structure and consisted of three thick layers; the outer layer had an unusual fine structure; the exosporium was also found.