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Applied Biochemistry and Microbiology (v.37, #4)
Laboratory Scale Photobioreactors by A. A. Tsygankov (pp. 333-341).
Growing phototrophic microorganisms consume light energy. These microorganisms most often suffer from light deficiency because of exponential decrease in the energy of light passing through an absorbing medium. Therefore, effective distribution of light within the cultures is needed for their intensive cultivation. This is possible in special devices called photobioreactors. The photobioreactors described in the literature are classified into several types according to their geometric features. Their advantages and drawbacks are analyzed. Criteria applicable to comparison of different photobioreactors are specified.
Degradation of Mineral Oil with a Strain of Acinetobacter calcoaceticus by E. V. Pleshakova; A. Yu. Muratova; O. V. Turkovskaya (pp. 342-347).
The Acinetobacter calcoaceticusstrain TM-31 has been isolated from a microbial assemblage of a pilot plant that purifies waste water polluted with mineral oil. This strain is capable of efficient degradation of components of mineral oil (alkanes, isoalkanes, and alkyl residues of the naphthene and arene fraction). The strain bears stably inherited plasmids of sizes 120, 9, and 8 kb, which can be transferred into plasmid-free cells of the parental strain and into bacteria of the genusPseudomonasand ensure the degradation of hexadecane and mineral oil.
Removal of Nonferrous Heavy Metals from Industrial Sewage Using Biosorbents by V. I. Zakharova; V. O. Ignat'ev; A. A. Korenevskii; Z. A. Avakyan; G. I. Karavaiko (pp. 348-353).
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.
Investigation of the Stability of an Association of Oil-Degrading Microorganisms in an Open System by E. N. Kobzev; S. B. Petrikevich; A. N. Shkidchenko (pp. 354-357).
Studies of the stability of an association of active hydrocarbon-oxidizing microorganisms grown on diesel fuel showed that not all members of the association were competitive in an open-flow system. The abundance of some strains considerably decreased during cultivation. One of the strain groups had consistently high cell titers both in the medium and on a support. This prompts the use these strains as degraders of diesel fuel.
Effects of Exogenous Factors on Enzymes of Carbon Metabolism in Thermoacidophilic Bacteria of the GenusSulfobacillus by E. N. Krasil'nikova; I. A. Tsaplina; L. M. Zakharchuk; T. I. Bogdanova (pp. 358-362).
Aerobic thermoacidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans1269Tand Sulfobacillus thermosulfidooxidanssubsp. asporogenes41 were shown to be resistant to stress factors, including high concentrations of Zn2+(0.8 M) and supraoptimal concentrations of H+(pH 1.2). The growth and biomass gain rates decreased, but bacteria retained their functions. The activity of nearly all enzymes involved in carbon metabolism decreased. Glucose was primarily metabolized via the Entner–Doudoroff pathway. The activity of tricarboxylic acid cycle enzymes decreased compared to that in cells grown under normal conditions. After saturation of the growth medium with 5 vol % CO2, sulfobacteria utilized glucose by the Embden–Meyerhof and pentose phosphate pathways under mixotrophic conditions.
Selection of a Mixed Culture of Cellulolytic Thermophilic Anaerobes from Various Natural Sources by N. V. Zyabreva; E. P. Isakova; V. V. Biryukov (pp. 363-367).
Microbial associations capable of converting cellulose-containing substrates to ethanol and organic acids were isolated from natural sources. The resulting mixed cultures utilized cellulose, cellobiose, glucose, maize residue, cotton, and flax boon producing ethanol (up to 0.9 g/l) and acetic acid (up to 0.8 g/l). The most complete conversion of cellulose-containing substrates occurred at 60°C and pH 7.0. The selected association of thermophilic anaerobic bacteria produced 0.64 g of ethanol per g substrate utilized at the ethanol/acetate ratio 4.7 : 1.
A Two-Stage Cultivation Technique for Producing Microbial Exopolysaccaride Ethapolan with Improved Rheological Properties by T. P. Pirog; Yu. R. Malashenko; S. K. Votselko (pp. 368-373).
A two-stage technique was proposed for cultivating producers of microbial exopolysaccharide ethapolan. The practical value of ethapolan is determined by its rheological properties. The use of a formaldehyde-supplemented medium at the second stage of cultivation improved the rheological properties of ethapolan without reducing its yield. This effect of formaldehyde was due to its binding to the exopolysaccharide, which altered the molecular-weight characteristics of the latter and protected cells against the toxic action of formaldehyde. At all stages of its purification, ethapolan had improved rheological properties, suggesting that it was tightly bound to formaldehyde.
Optimum Conditions for Transformation of Maleic Acid by Immobilized Cells of Alcaligenes xylosoxidanssubsp. xylosoxidans260 by I. Yu. Safronova; E. V. Semenova (pp. 374-375).
Immobilized cells of Alcaligenes xylosoxidanssubsp. xylosoxidans260 transformed 98% of the maleic acid (initial concentration of 5.0 g/l medium) under periodic conditions for 48 h. Free cells transformed only 26% of the substrate in 96 h. Immobilized cells of a selected S-variant ofA. xylosoxidanstransformed the maleate (30.0 g/l) entirely in 96 h during batch cultivation and only 15.0 g/l of the maleate in continuous cultivation at a flow rate of 0.03 h–1.
Immobilization of Chloroperoxidase from Serratia marcescens by Yu. V. Preobrazhenskaya; V. N. Burd'; A. I. Voskoboev (pp. 376-379).
A bacterial non-heme chloroperoxidase from Serratia marcescensW 250 was immobilized in calcium alginate gel. Methods for stabilization of the immobilized enzyme were developed, and some kinetic parameters of the immobilized preparations were determined. The enzyme encapsulated into the gel granules in the presence of potassium ferricyanide followed by treatment with glutaraldehyde demonstrated the highest stability under the reaction conditions.
Effect of a Cloned DNA Fragment from Streptomyces chrysomallusNo. 2 on the Metabolism of Certain Streptomyces Strains by T. Yu. Novozhilova; T. A. Alekhova (pp. 380-387).
The effects on a cloned DNA fragment carrying an actinomycin resistance determinant on physiological processes in strains of streptomycetes with various potencies in producing this antibiotic, their inactive mutants, and the model strain ofStreptomyces lividans66 were studied. This fragment was shown to modulate bacterial resistance to actinomycin and biosynthesis of antibiotics.
Galactomannan from Ambiguous Crazyweed (Oxytropis ambigua(Pall.) DC) by N. M. Mestechkina; I. E. Lobanova; O. V. Anulov; V. D. Shcherbukhin (pp. 388-391).
A galactomannan with a molecular weight of 735 kDa was first isolated and purified from seeds of ambiguous crazyweed Oxytropis ambigua(Pall) DC (family Leguminosae) with a yield of 3.6%. Its aqueous solutions displayed an optical activity ([α] D = 73.32°) and high viscosity ([η] = 644 ml/g). Chemical analysis and 13C-NMR spectroscopy revealed the presence of D-mannopyranose and D-glucopyranose in the heteropolysaccharide at a molar ratio of 1.39 : 1. The linear backbone of its macromolecule consists of 1,4-β-D-mannopyranose residues. Single α-D-galactose residues substitute 72% of the mannoses to form branches.
Phenolic Substances in Medicinal Plants by M. P. Kolesnikov; V. K. Gins (pp. 392-399).
Compositions of phenolic substances were studied in the leaves of 21 species of medicinal plants. Flavonoid levels varied from 1.94 to 5.42%, whereas total amounts of monomeric polyphenols and hydroxybenzoic acids were estimated as 0.27 to 0.57%; hydroxycinnamic acids and their esters with quinic acid, 0.09 to 0.18%. Condensed and polymerized polyphenols were detected in amounts of 0.41 to 1.20%. Qualitative compositions of flavonoids in leaves of the seven plants studied were presented. The developed analytical procedures may be useful for plant polyphenol studies and as a basis for hemotaxonomy.
The Specific Density of a Leaf as a Characteristic of the Photosynthetic Apparatus by I. I. Chernyad'ev (pp. 400-405).
At early stages of ontogeny (up to 50–60% of the maximum leaf area) of wheat (Triticum aestivumL.), meadow fescue (Festuca pratensisHuds.), reed fescue (F. arindinaceaSchreb.), and sugar beet (Beta vulgarisL. var. saccharifera(Alef) Krass), there is a correlation between changes in the specific leaf density (SLD); photosynthetic CO2assimilation rate; activity of the key photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39); and the concentrations of chlorophyll (Chl) a, Chl b, carotenoids, and soluble leaf proteins. However, the SLD does not correlate with the activity of phospho(enol)pyruvate carboxylase (EC 4.1.1.31). Senescence was accompanied by a decrease in the leaf SLD. Treatment with cytokininomimetics (6-benzylaminopurine and Metribuzin) caused an increase in the SLD. The specific leaf density is suggested to be a structural and functional characteristic of the photosynthetic apparatus of agricultural plants.
Gallic acid: a Potent Inhibitor of Tetramethylbenzidine Peroxidation in Aqueous and Micellar Media by E. I. Karaseva; T. V. Nikiforova; D. I. Metelitsa (pp. 406-412).
Gallic acid competitively inhibited 3,3",5,5"-tetramethylbenzidine peroxidation both in 0.01 M of phosphate buffer (pH 6.4) (K I= 13.3 μM) and in reversed aerosol OT micelles of different hydration degrees dispersed in heptane (K I= 21.3 to 29.3 μM). The average number of free radical particles terminated by one inhibitor molecule (f) was estimated to be 1.3 to 1.6 in aqueous buffer solutions and 1.08 to 2.72 in reversed micelles, depending on their hydration.
Changes in the Composition of Volatile Compounds during Aging of Dry-cured Sausages by T. A. Misharina; V. A. Andreenkov; E. A. Vashchuk (pp. 413-418).
The change in the composition of volatile components during aging and storage of dry-cured sausages containing a mixture of Lactobacillus plantarumand Staphylococcus carnosusas fermenting cultures was studied by high-performance capillary gas chromatography and gas chromatography-mass spectrometry. A total of 52 compounds were identified. It was found that sausage storage is accompanied by a significant increase in the concentration of flavoring aldehydes. The terpene concentration monotonically increases with sausage aging and storage.
Lactic Acid Bacteria and Yeasts as Means of Decreasing Wine Acidity by G. S. Eliseeva; S. S. Nagornaya; O. E. Zherebilo; V. S. Podgorsky; E. A. Ignatova (pp. 419-424).
Two hundred monocultures of lactic acid bacteria and 30 associations of yeasts and lactic acid bacteria have been studied. A stable association was developed which was capable of decreasing wine acidity. The association contained two species of bacteria, Leuconostoc oenosand Pediococcus pentosaceus, and the yeast Saccharomyces cerevisiae. The physiology of the microorganisms was studied, and their effects on the chemical composition of wines were determined.
A New Method for Differential Quantitative Assay of Zeatin and Zeatin Riboside by A. N. Blintsov; M. A. Gusakovskaya; I. P. Ermakov (pp. 425-429).
A new method is proposed for differential quantitative assay of two major endogenous cytokinin forms. It is based on determination of two effective parameters—concentrations of zeatin and zeatin riboside—with the use of appropriate antigens as standards. The method can be used for determining cytokinins in small samples of plant tissues without extract fractionation. This study pioneers the quantitation of changes in the hormonal status of ovules and ovaries of Triticum aestivumL. at early stages of embryogeny. A gradual increase in the content of the active and storage forms of the hormones from the ovary to the ovule was revealed.