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Applied Biochemistry and Microbiology (v.42, #2)
Microbial producers of plant growth stimulators and their practical use: A review by E. A. Tsavkelova; S. Yu. Klimova; T. A. Cherdyntseva; A. I. Netrusov (pp. 117-126).
The ability of pro-and eukaryotic microorganisms to synthesize growth-stimulating phytohormones is reviewed, with emphasis on the pathways of biosynthesis of these compounds and their effects on the physiological and biochemical properties of the producers. Phytohormones are viewed as specific mediators in interactions between various organisms inhabiting the same ecological niche, the biological role of which is not limited to processes taking place in plants. In addition to setting forth the theoretical aspects of this problem, the review underscores the need to utilize such producer microorganisms in plant cultivation and biotechnology
Synthesis and properties of horseradish peroxidase copolymers by L. P. Budnikova; A. N. Eryomin (pp. 127-133).
Conditions for copolymerization of native and sodium periodate-oxidized horseradish peroxidase (HTP; EC 1.11.1.7) have been optimized. Copolymerization products have been characterized electrophoretically, spectrally, and kinetically. Copolymers containing 2–3, 4, 5–7, and 9–10 molecules of the enzyme were found among the products of polymerization. The copolymers had lower values of D 403/D 280 than HRP. The copolymers had more ordered structures than the original HRP. Comparison of the thermal stability and kinetic characteristics of the fractions differing in the ratio of copolymers to the monomeric enzyme demonstrated that the polymeric products were more stable than HRP (in terms of resistance to high temperature or inhibitory effects of H2O2), but their kinetic activity was, on the whole, lower than that of the original enzyme.
Immobilization of chloroperoxidase from Serratia marcescens in semi-permeable protein membranes by Yu. V. Preobrazhenskaya; Yu. A. Bogdevich; V. N. Burd’ (pp. 134-137).
A method for the immobilization of chloroperoxidase from the bacterial strain Serratia marcescens in semi-permeable membranes was developed based on the following proteins: bovine serum albumin, gelatin, ribonuclease, cytochrom C, and the protein of the covering layer of Bacillus sphaericus cells. Estimation of the activity and stability of immobilized preparations in a batch reactor was carried out.
Immobilization of extracellular glucose oxidase from Penicillium funiculosum 46.1 on gels of aluminum or zinc hydroxides by A. N. Eryomin; T. V. Semashko; R. V. Mikhailova (pp. 138-144).
Different methods of immobilization of extracellular glucose oxidase (GO) from Penicillium funiculosum 46.1 on gels of aluminum or zinc hydroxides have been compared. GO from the culture liquid filtrate (CLF) associated with Zn(OH)2 but not Al(OH)3 gels. Preparation of samples of immobilized GO does not require isolation of the enzyme (CLF may be used). GO immobilized on Zn(OH)2 gels from CLF was 1.6 times more efficient in catalyzing D-glucose oxidation than the enzyme contained in the original culture liquid. Crosslinking of gel-adsorbed CLF proteins affected the properties of GO adversely and to a considerable extent. Various means of polymerization and immobilization of GO isolated from CLF have been studied. Optimum results were obtained when GO polymeric products were pre-synthesized in solution, followed by adsorption to Al(OH)3, but not Zn(OH)2 gels. The catalytic efficiency of GO immobilized on a Zn(OH)2 gel was significantly lower than that of the enzyme associated with Al(OH)3.
Immobilized glucoamylase: A biocatalyst of dextrin hydrolysis by G. A. Kovalenko; L. V. Perminova; G. V. Plaksin; T. V. Chuenko; O. V. Komova; N. A. Rudina (pp. 145-149).
Heterogeneous biocatalysts of starch saccharification based on glucoamylase and carbon-containing carriers were obtained, and their biocatalytic properties in the enzymatic hydrolysis of corn dextrins were studied. It was shown that the morphology of the surface carbon layer of carriers markedly affected the properties of biocatalysts. Glucoamylase immobilized by adsorption on the surface of carriers covered with a layer of catalytic filamentous or pyrolytic carbon had the maximum enzymatic activity and stability, whereas biocatalysts prepared on the basis of carriers that had no carbon layer or were covered with graphite-like surface carbon had a low activity and stability.
Enzymatic conversion of invertase substrates in a water-organic medium by D. T. Mirzarakhmetova; M. M. Rakhimov; S. Kh. Abdurazakova; Z. R. Akhmedova (pp. 150-155).
The behavior of intact and immobilized invertase in aqueous and water-organic media has been studied. In a water-organic medium, the transferase properties of the enzyme changed: pH optima of intact and immobilized invertase undergo shifts of 0.5 units; the temperature optimum decreases (50°C and 25°C in aqueous and water-organic media, respectively). The extent of conversion of isoamyl alcohol in water-organic medium shows a dependence on several factors (the enzyme and substrate concentrations; amount of the organic phase; and duration of the enzyme incubation with the substrate). Optimum parameters of isoamyl alcohol conversion were used for transforming fusel alcohols into alkyl fructosides. The results of this applied research have important practical implications (conversion of fusel oils of alcoholic beverages).
The prospects of using bacteria of the genus Rhodococcus and microbial surfactants for the degradation of oil pollutants by E. V. Karpenko; R. I. Vil’danova-Martsishin; N. S. Scheglova; T. P. Pirog; I. N. Voloshina (pp. 156-159).
The possibility of accelerating oil degradation by an enrichment culture of oil-oxidizing microorganisms in the presence of bacteria of the genus Rhodococcus and microbial surfactants was studied. It was shown that the degree of consumption of crude oil (2vol %) after 192 h of enrichment culture growth reached 84%. Inoculation of the active hydrocarbon-oxidizing strain Rhodococcus erythropolis EK-1 and exogenous surfactants produced by Pseudomonas sp. PS-27 increased this degree to 90 and 93–94%, respectively. On the grounds of these results, efficient methods of purification of the environment from oil pollutants can be developed.
Change in the composition of a bacterial association degrading aromatic compounds during oil sludge detoxification in a continuous-flow microbial reactor by A. B. Gafarov; A. V. Panov; A. E. Filonov; A. M. Boronin (pp. 160-165).
Analysis of oil sludge by direct plating and enrichment cultivation revealed 16 strains degrading aromatic compounds. After 30 days of cultivation in a continuous-flow microbial reactor, 17 more degrader strains were isolated. Genotyping of these strains showed that they were taxonomically diverse, and the range of strains degrading naphthalene, benzene, toluene, ethylbenzene, and xylenes depended on isolation methods. Direct plating yielded more aromatic degraders than enrichment cultivation. A microbial association different from that existing before the enrichment cultivation was obtained in the laboratory continuous-flow reactor.
Biological activity of probiotic microorganisms by G. I. Novik; A. A. Samartsev; N. I. Astapovich; M. A. Kavrus; A. N. Mikhalyuk (pp. 166-172).
Adaptation of bifidobacteria and lactic acid bacteria to nutrient media with increased concentrations of bile (1%) and protein substrates of animal origin allowed the variants resistant to bile and displaying a high production of proteolytic enzymes (active within the pH range of 2.5–9.0) to be selected. Administration of the preparations involving the selected bifidobacteria and lactic acid bacteria assisted in the normalization of the intestinal microflora and activation of protein metabolism in the organism of animals. Specifically, it increased the total protein level in blood serum and redistributed protein fractions, increasing the content of globulins and decreasing albumin concentration.
Antagonistic activity of actinomycetes of Lake Baikal by I. A. Terkina; V. V. Parfenova; T. S. Ahn (pp. 173-176).
It was demonstrated that the actinomycetes of Lake Baikal are strong antagonists of other microorganisms. Representatives of the genera Streptomyces and Micromonospora inhibit the growth of bacteria isolated from the lake, as well as of antibiotic-resistant microorganisms causing various human diseases. Baikal actinomycetes display a wide range of antagonistic activity and are potential producers of new biologically active substances.
Long-term storage of obligate anaerobic microorganisms in glycerol by A. L. Bryukhanov; A. I. Netrusov (pp. 177-180).
We evaluated the possibility of storing the cultures of obligate anaerobic microorganisms (clostridia, acetogenic and sulfate-reducing bacteria, and methanogenic archaea) in 25% glycerol at −70°C for a long time (up to 3 years). This method of storage is adequate for preserving cell viability in the majority of obligate anaerobes.
The effect of acid proteinases on the activity and stability of glucoamylase preparations by N. M. Rakhimova; Kh. T. Khasanov; K. D. Davranov (pp. 181-185).
It was demonstrated that the presence of acid proteinases in the preparation isolated from Aspergillus awamori decreased the activity and stability of glucoamylase. Patterns of changes in the enzymatic activity and stability of glucoamylase at increased temperature and various pH values were studied over a long-term storage. A biospecific sorbent for removal of acid proteinases was synthesized and glucoamylase preparations free of proteolytic activity were produced.
Extracellular proteolytic enzymes of microscopic fungi from thermal springs of the Barguzin Valley (Northern Baikal region) by B. B. Bazarzhapov; E. V. Lavrent’eva; Ya. E. Dunaevskii; E. N. Bilanenko; B. B. Namsaraev (pp. 186-189).
Production of extracellular proteolytic enzymes was studied in thermophilic fungi Paecelomyces variotii and Aspergillus carneus, isolated from thermal springs of the Barguzin Valley. Protease synthesis in these fungi requires protein in the ambient medium. The composition of the enzymes secreted by A. carneus depends on the kind of carbohydrate present in the medium. The proteinase of this fungus digests synthetic substrates and gelatin (optimum pH 7.7). It belongs to neutral serine proteases. Extracellular P. variotii proteases digest gelatin (optimum pH 9.7–10.4). According to inhibitor analysis data, they can be classified as alkaline metalloproteinases and serine proteinases.
Physiological aspects of intensifying yeast growth by A. N. Shkidchenko (pp. 190-194).
The possibilities of intensifying yeast growth during flow cultivation via an increase in the rate of medium flow and the concentration of carbon-containing substrate are considered. It is found that stabilization of the optimum specific substrate loads provides the maximum economic coefficient of the process. Stabilization of the optimum specific loads of carbon-containing substrates during a three-stage flow cultivation of yeasts in a medium with n-alkanes allowed the throughput of a battery of fermenters to be elevated 1.84-fold. Alternation of flow chemostatic and turbidostatic yeast cultures was accompanied by a fivefold increase in the maximum specific growth rate.
Soybean lectin as a component of a composite biopreparation involving Bradyrhizobium japonicum 634b by E. V. Kirichenko; L. V. Titova (pp. 195-199).
The effects of the composite biopreparation Bralec (involving the soybean-specific root nodule bacterium Bradyrhizobium japonicum strain 634b and soybean lectin at concentrations of 500, 50, and 5 μg/ml as major components) on the development and functional activity of soybean-rhizobium symbiosis (development phases of one leaf, four true leaves, and budding) was studied. It was demonstrated that pretreatment of seed with this preparation stimulated the development of both the macro-and microsymbionts. The experimental plants displayed an active accumulation of biomass (4–42% higher compared with the variant with inoculation), development of root nodules (the number increased by 11–110% and the weight by 27–157%), and elevated nitrogen-fixing activity (by 45–204%). The soybean yield increased by 8–10% upon treatment with Bralec 500 and Bralec 5 as compared with the traditional seed bacterization with root nodule bacteria.
Effect of the molecular weight of chitosan on its antiviral activity in plants by S. N. Kulikov; S. N. Chirkov; A. V. Il’ina; S. A. Lopatin; V. P. Varlamov (pp. 200-203).
The effect of the molecular weight of chitosan on its ability to suppress systemic infection of bean mild mosaic virus in bean (Phaseolus vulgaris L.) plants was studied. The enzymatic hydrolysate of low-molecular-weight chitosan was successively fractionated by ultrafiltration through membranes with decreasing pore size. In total, four chitosan fractions with a weight-average molecular weight varying from 1.2 to 40.4 kDa were obtained. It was shown that the treatments of bean plants with these fractions (chitosan concentration, 10 or 100 μg/ml) inhibited virus accumulation and systemic propagation. The degree of chitosan-induced antiviral resistance increased as the molecular weight of chitosan decreased. The monomers comprising the chitosan molecule—glucosamine and N-acetylglucosamine—exhibited no antiviral activity.
Modeling of lactic acid fermentation of leguminous plant juices by R. A. Shurkhno; Sh. Z. Validov; A. M. Boronin; R. P. Naumova (pp. 204-209).
Lactic acid fermentation of leguminous plant juices was modeled to provide a comparative efficiency assessment of the previously selected strains of lactic acid bacteria as potential components of starter cultures. Juices of the legumes fodder galega, red clover, and alfalfa were subjected to lactic acid fermentation in 27 variants of the experiment. Local strains (Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, and Lactobacillus sp. RS 4) and the collection strain Lactobacillus plantarum BS 933 appeared the most efficient (with reference to the rate and degree of acidogenesis, ratio of lactic and acetic acids, and dynamics of microflora) in fermenting fodder galega juice; Lactobacillus sp. RS 1, Lactobacillus sp. RS 2, Lactobacillus sp. RS 3, Lactobacillus sp. RS 4, and L. plantarum BS 933 were the most efficient for red clover juice. Correction of alfalfa juice fermentation using the tested lactic acid bacterial strains appeared inefficient, which is explainable by its increased protein content and a low level of acids produced during fermentation.
Characteristics of immunoaffinity chromatography and a new method for isolation of human thyroid peroxidase from subcellular fractions of thyroid gland by O. V. Tsyganova; E. P. Kiseleva; I. I. Vashkevich; A. G. Pryadko; O. V. Sviridov (pp. 210-219).
A system for quantitative determinations of human thyroid peroxidase (TPO) in biological fluids has been obtained, based on the use of enzyme-linked immunosorbent assay. The immunochemical properties of TPO were studied under variable conditions and a new method for isolating the protein from the microsomes, mitochondria, and cytosol of thyroid glands of patients with diverse thyroid diseases was developed. The procedure involves solubilization of subcellular fractions with detergents, their sonication, two sequential runs of chromatography (on sorbents with immobilized monoclonal antibodies against TPO and goat anti-human immunoglobulin antibodies), treatment with ribonuclease, and dialysis. Highly purified preparations of intact TPO and a product of its limited trypsinolysis are expected to be used as research tools and components of high-sensitivity immunoassays.
Changes in the content of wheat germ agglutinin in hydrogen peroxide-treated plants by A. V. Babosha (pp. 220-223).
The content of wheat germ agglutinin (WGA) in hydrogen peroxide-treated seedlings was studied by indirect competitive enzyme-linked immunosorbent assay. WGA content in roots showed a transitory increase: at 10 mM hydrogen peroxide, the maximum level was observed after 2 h; at 1 mM hydrogen peroxide, the maximum occurred 2 or 24 h after treatment. Lectin induction by hydrogen peroxide is viewed as an element of a feedback mechanism limiting the operation of defense responses during pathogenetic processes.
Dependence of alcohol binding from aqueous dispersions on physicochemical properties of starch by T. A. Misharina; A. L. Samusenko; M. A. Kalinchenko (pp. 224-227).
Binding of alcohols from aqueous dispersions of native cornstarches differing in amylose content was studied by means of capillary gas chromatography. The efficiency of this process was compared with that of binding to gelatinized starches. Studies of native and gelatinized starches showed that the amount of bound substances depended linearly on their initial concentration. Binding of alcohols did not differ in native and gelatinized normal starch and high amylose starch. The efficiency of binding increased with the length of the alkyl substituent. It should be emphasized that the highest efficiency of binding was observed with native starch. Native amylopectin starch was less potent than gelatinized starch in binding hexanol. The degree of alcohol binding was much lower in cryotextures of gelatinized starch.