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Applied Biochemistry and Microbiology (v.36, #6)
Ontogenetic Changes in the Photosynthetic Apparatus and Effects of Cytokinins (Review) by I. I. Chernyad'ev (pp. 527-528).
Data on structural and functional changes in the photosynthetic apparatus of agricultural plants are presented. Results of experiments with the regulatory effects of cytokinin-like phytohormones on photosynthesis are discussed. Cytokinins are involved in the structural formation and maintenance of the photosynthetic apparatus, stomatal function, supply of CO2 to carboxylation sites through the leaf mesophyll, synthesis of pigments and enzyme systems, and regulation of photoreduction and carbon metabolism. Possible mechanisms mediating the regulatory effects of cytokinins are discussed.
The 25th Anniversary of the Foundation of the State Research Center for Applied Microbiology: Results and Prospects
by N. N. Urakov (pp. 540-543).
Microbiological Degradation of Asymmetric Dimethylhydrazine, a Toxic Rocket Fuel Ingredient by V. A. Chugunov; I. I. Martovetskaya; R. I. Mironova; V. M. Fomchenkov; V. P. Kholodenko (pp. 544-549).
The possibility of microbiological cleaning of water and soil polluted with asymmetric dimethylhydrazine (ADMH), a highly toxic ingredient of rocket fuel (IRF), was studied. Several isolates (bacteria, yeast, and micromycetes) capable of utilizing ADMH as the only source of nitrogen, carbon, and energy were isolated from IRF-polluted tundra soil. Acceleration of IRF biodegradation was achieved using a biosorbent that involved cells of the degrader strain immobilized on granulated activated charcoal. Biological testing in Escherichia coli and cereals (wheat and barley) demonstrated that biodegradation significantly decreased the integral toxicity of solutions containing ADMH, suggesting its utility for microbiological cleaning of polluted territories.
Studies of Initial Stages of Biocorrosion of Steel by S. K. Jigletsova; V. B. Rodin; V. S. Kobelev; N. V. Aleksandrova; G. E. Rasulova; V. P. Kholodenko (pp. 550-554).
Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8–10 h after inoculation. The number of viable cells was virtually unchanged over one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even after incubation for only 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in significant damage to metals.
Microbial Destructors of Certain Chlorinated Organics by E. V. Mitsevich; I. P. Mitsevich; V. V. Perelygin (pp. 555-558).
The possibility of isolation of microorganisms, which are potential destructors of chlorinated organics, from aged Vietnamese soils polluted with dioxine-containing defoliants was demonstrated. As an example, the ability of one isolated strain to metabolize pentachlorophenol and 2,4-dichlorophenoxyacetic acid was shown under laboratory conditions. An attempt was made to identify intermediates of pentachlorophenol metabolism using HPLC.
Effect of Space Flight Conditions on the Properties of Hydrocarbon-Oxidizing Bacteria by Z. M. Ermolenko; I. I. Martovetskaya; V. A. Chugunov; V. P. Kholodenko (pp. 559-563).
Results of experiments on the Mir space station (EO-25 and EO-26) demonstrated that the conditions of orbital flight, primarily cosmic radiation, were a mutagenic factor affecting both the genotype and phenotype of an oil-oxidizing bacterial strain, Mycobacterium flavescensEX-91. The emerging mutants differed from the original culture by the rate of colony growth and the ability to ferment certain carbohydrates or synthesize β-galactosidase. Changes in the rate of utilization of raw oil and individual hydrocarbon types (constituting model mixtures) suggest that cosmic radiation may serve as a means of obtaining mutant clones of microorganisms with new properties.
Plant Biotests for Soil and Water Contaminated with Oil and Oil Products by V. N. Petukhov; V. M. Fomchenkov; V. A. Chugunov; V. P. Kholodenko (pp. 564-567).
Reactions of higher plants (mustard, oat, rye, lettuce, dill and barley) and microalgae (Euglena gracilis) to the contamination of soil and water with oil and oil products was studied. The germination of seeds was analyzed. The length of sprouts, dry biomass and length of plant roots, as well as the optical density of microalgal broth culture were determined. Negative effects of soil and water contamination with oil and oil products on plant and microalgal parameters examined was shown. After biological destruction of contaminants by an association of destructor strains (Acinetobactersp., Mycobacterium flavescens andRhodoccocussp.), the toxicity of contaminated mediums decreased. The data suggest that the integral toxicity of soil and water contaminated with oil and oil products and toxicity changes during biodestruction of these pollutants can be analyzed by using plant test organisms.
Assessment of the Integral Toxicity of Aquatic Medium Contamination with Oil and Oil Products Using Bacterial Tests by V. M. Fomchenkov; I. A. Irkhina; I. A. Novikov; B. N. Gurov; V. A. Chugunov; V. P. Kholodenko (pp. 568-571).
A biotest kit was used to assess the integral toxicity level of aquatic environment contamination with oil and oil products. The integral toxicity dynamics were also monitored during biodegradation of oil and oil products by an association of oil-degrading strains, including Acinetobacter sp., Mycobacterium flavescens, and Rhodococcussp. The following bacterial tests were used: the bioluminescence (BL) test based on Photobacterium leiognathi; electroorientation (EO), optoosmotic (OO), and growth tests; and the reducing activity (RA) test based on an Agrobacterium radiobacter culture. No significant increase in the integral toxicity level of the aquatic medium was observed when diesel fuel and kerosene contamination had been subjected to biodegradation. Although rapid biotests (EO, OO, RA, and BL) detected a pronounced increase in the integral toxicity of the aquatic environment, long-term growth biotests revealed no statistically significant increase in the toxicity level.
Development and Testing of the Biosorbent Ekosorb Prepared from an Association of Oil-Oxidizing Bacteria for Cleaning Oil-Polluted Soils by V. A. Chugunov; Z. M. Ermolenko; S. K. Jigletsova; I. I. Martovetskaya; R. I. Mironova; N. A. Zhirkova; V. P. Kholodenko (pp. 572-576).
A biosorbent containing an association of oil-oxidizing bacteria as the main constituent was developed, in which Lessorb, a product of moss and wood thermal processing, was used as a carrier. Xeroprotectors preserving the cell viability and oil-oxidizing activity in the biosorbent on drying and after long-term storage were selected. The use of this biosorbent for cleaning oil-polluted sod-podzol soils showed a two- to threefold cleanup rate acceleration at different pollution levels (8 and 24 l/m2), especially in the presence of a nitrogen–phosphate fertilizer. The biosorbent increased the populations of certain groups of soil microorganisms and the total soil biological activity.
Development and Application of a Liquid Preparation with Oil-Oxidizing Bacteria by V. A. Chugunov; Z. M. Ermolenko; S. K. Zhigletsova; I. I. Martovetskaya; R. I. Mironova; N. A. Zhirkova; V. P. Kholodenko; N. N. Urakov (pp. 577-581).
An association of four bacterial strains with high oil-oxidizing and bioemulsifying activities, psychrophilicity, resistance to chemical pollutants, and lack of pathogenicity was selected from a collection of natural oil-oxidizing microorganisms. A new liquid preparation containing stabilizers and preservatives that maintain cell viability and oil-oxidizing activity during long-term storage was developed. A field experiment in oil-polluted sod-podzol and clay sand soils demonstrated that this preparation accelerated the biodegradation of oil and its individual fractions, especially in the presence of mineral and organic fertilizers. Treatment of oil-polluted soil with this preparation and additives decreased the oil-induced suppression of certain groups of soil microflora.
Microorganisms as Possible Indicators of General Soil Pollution by Dioxin-Containing Defoliants by E. V. Mitsevich; I. P. Mitsevich; V. V. Perelygin; Do Ngok Lan'; Nguen Thu Hoai (pp. 582-588).
The diversity of microorganisms from soils treated in the past with various dosages of dioxin-containing defoliants was studied. Population alterations dependent on dioxin concentrations were elucidated. Soil fungi and, to a smaller extent, actinomycetes were found to be the most sensitive to dioxins.
Development of Biological Methods for Controlling the Aerobic Microorganism–Induced Corrosion of Carbon Steel by V. B. Rodin; S. K. Jigletsova; V. S. Kobelev; N. A. Akimova; N. V. Aleksandrova; G. E. Rasulova; V. P. Kholodenko (pp. 589-593).
Cocultivation of destructor microorganisms and their antagonists decreases the corrosion loss of carbon steel by 20 to 80%. It was found that a microorganism can either accelerate or inhibit corrosion, depending on the nutrient. The magnitude of the effect on corrosion depends on the ability of the microorganism to respond to changes in the nutrient medium composition by releasing acidic or alkaline metabolites.
Chemicomicrobiological Diagnostics of Stress Corrosion Cracking of Trunk Pipelines by V. P. Kholodenko; S. K. Jigletsova; V. A. Chugunov; V. B. Rodin; V. S. Kobelev; S. V. Karpov (pp. 594-601).
Samples of soil, subsoil, electrolyte, corrosion products, and protective coating were taken after excavating pipelines. The depth of stress corrosion cracking of the pipe steel was mostly related to counts of sulfate-reducing and denitrifying bacteria. In certain types of soil, crack depth correlated with the number of acid-producing microorganisms and aerobic chemoorganotrophs (saprophytes). A correlation was found between the extent of stress corrosion cracking of pipelines and the contents of mobile reduced iron, sulfides, organic carbon, and a number of other parameters of the surrounding soil.
Use of Biocides as Agents against Microorganism-Induced Corrosion Increases Ecological Safety by S. K. Jigletsova; V. B. Rodin; V. S. Kobelev; N. A. Akimova; N. V. Aleksandrova; G. E. Rasulova; R. I. Mironova; V. P. Noskova; V. P. Kholodenko (pp. 602-608).
Five synergistic combinations of biocides have been identified, of which kathon plus copper sulfate is the most efficient against Serratia marcescens. Depending on the ratio of the biocides, the active concentrations needed to maintain the synergistic effect can be decreased 4- to 20-fold. Combinations of biocides with salts promoting steel passivation (such as carbonates and phosphates) have been developed, which are more potent in decreasing corrosion-induced losses of mild steel than biocides and salts taken in isolation. Biocides should be introduced into systems susceptible to biocorrosion at the start of their exploitation, otherwise higher concentrations or synergistic compositions have to be used.
Direct Quantitative Evaluation of the Effects of Biocides on Pseudomonas fluorescens in Various Nutrient Media by V. B. Rodin; S. K. Jigletsova; N. A. Akimova; V. P. Kholodenko (pp. 609-612).
A method for quantitative evaluation of the effects of biocides is presented. The method was tested in experiments with Pseudomonas fluorescens grown on various agar nutrient media. The effective concentrations of biocides that decreased the maximum specific rate of the colony biomass growth (μ"m) were called S (suppressing) concentrations, and concentrations that decreased the number of colony-forming units (CFU) were taken as L (sublethal) concentrations. The efficiency of the reported approach was demonstrated in experiments with three biocides tested in four nutrient media. It was found that the biocide sensitivity of Pseudomonas fluorescens varied by a factor of 30, depending on the amount and type of the nutrient substrate.
V. V. Mikhailov, T.A. Kuznetsova, and G. B. Belyakov, Marine Microorganisms and Their Biologically Active Secondary Metabolites, Vladivostok: Dal'nauka, 1999
by I. E. Mishustina (pp. 613-614).
K. ten Tate and S. A. Laird, The Commercial Use of Biodiversity. Earthscan Publications Ltd., London, 1999, 398 p. ISBN 1 85383 334 7
by L. V. Kalakutskii (pp. 615-616).