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Applied Biochemistry and Microbiology (v.39, #4)
Lytic Enzymes of Trichoderma and Their Role in Plant Defense from Fungal Diseases: A Review by N. A. Markovich; G. L. Kononova (pp. 341-351).
Lytic enzymes of mycoparasitic fungi of the genus Trichoderma, capable of suppressing a number of fungal phytopathogens that originate in air or soil, are reviewed. The topics analyzed include (1) regulation of production of chitinases, β-1,3-glucanases, and proteases; (2) molecular and catalytic properties of purified enzymes; and (3) their in vitro ability to degrade cell walls and inhibit spore germination or germ-tube elongation in various phytopathogenic fungi. Among the results summarized are reports of cloning and expression of genes coding for certain lytic enzymes of Trichoderma spp. These genes are used for obtaining plant transgenes with increased resistance to fungal diseases and Trichoderma transformants that produce higher levels of one lytic enzyme (a chitinase or protease) and thereby exhibit a more pronounced ability to suppress phytopathogenic fungi.
Inhibition of Peroxidase-Catalyzed Oxidation of Aromatic Amines by Substituted Phenols by D. I. Metelitza; I. V. Naumchik; E. I. Karasyova; G. I. Polozov; O. I. Shadyro (pp. 352-362).
Peroxidase-catalyzed oxidation of o-phenylene diamine (OPD) was competitively inhibited by trimethylhydroquinone (TMHQ), 4-tert-butylpyrocatechol (InH5), and 4,6-di-tert-butyl-3-sulfanyl-1,2-dihydroxybenzene (InH6). InH6 was the most efficient inhibitor (K i = 11 μM at 20°C in 0.015 M phosphate–citrate buffer, pH 6.0). The effects of InH5 and InH6 were not preceded by periods of induction of OPD oxidation products (contrary to TMHQ). Peroxidase-catalyzed oxidation of tetramethylbenzidine (TMB) was noncompetitively inhibited by InH6 and 3-(2-hydroxyethylthio)-4,6-di-tert-butylpyrocatechol (InH4), whereas o-aminophenol acted as a mixed-type inhibitor. The effects of all three inhibitors were preceded by an induction period, during which TMB oxidation products were formed. Again, InH6 was the most efficient inhibitor (K i = 16 μM at 20°C in 0.015 M phosphate–citrate buffer supplemented with 5% ethanol, pH 6.0). Judging by the characteristics of the inhibitors taken in aggregate, it is advisable to use the pairs OPD–InH5 and OPD–InH6 in systems for testing the total antioxidant activity of human biological fluids.
Isolation of myo-Inositol from Solutions by Enzymatic Biotransformation by E. N. Reut; M. M. Rakhimov (pp. 363-367).
The transferase reaction between phospholipids and inositol catalyzed by phospholipase D was studied at interfaces in water–organic solvent systems. Optimum conditions were determined for phosphatidylinositol synthesis in heterogeneous water–organic solvent systems. Hydrophobic components (phospholipids) were readily separated from water-soluble products (alcohols) in systems with organic solvents. In the hexane–water system, addition of methanol (an alcohol substrate) to the reaction medium displaced myo-inositol from the molecule of phosphatidylinositol. myo-Inositol was isolated from the mixture of its isomers using a two-step transferase reaction catalyzed by phospholipase D.
Extracellular Glucose Oxidase of Penicillium funiculosum 46.1 by T. V. Semashko; R. V. Mikhailova; A. N. Eremin (pp. 368-374).
A method for isolating extracellular glucose oxidase from the fungus Penicillium funiculosum 46.1 using ultrafiltration membranes was developed. Two samples of the enzyme with a specific activity of 914–956 IU were obtained. The enzyme exhibited a high catalytic activity at pH above 6.0. The effective rate constant of glucose oxidase inactivation at pH 2.6 and 16°C was 2.74 × 10–6 s–1. This constant decreased significantly as the pH of the medium increased (4.0–10.0). The temperature optimum for glucose oxidase–catalyzed β-D-glucose oxidation was in the range 30–65°C. At temperatures below 30°C, the activation energy for β-D-glucose oxidation was 6.42 kcal/mol; at higher temperatures, this parameter was equal to 0.61 kcal/mol. Kinetic parameters of glucose oxidase–catalyzed β-D-glucose oxidation depended on the initial concentration of the enzyme in the solution. Glucose oxidase also catalyzed the oxidation of 2-deoxy-D-glucose, maltose, and galactose.
Extracellular Laccases from Cerrena unicolor 059, Cerrena unicolor 0784, and Pleurotus oastreatus 0432: A Comparative Assay by E. V. Stepanova; T. V. Pegasova; V. P. Gavrilova; E. O. Landesman; O. V. Koroleva (pp. 375-381).
Laccases of the basidiomycetes Cerrena unicolor 059, C. unicolor 0784, and Pleurotus oastreatus 0432 were subjected to a comparative study. The enzymes were isolated as homogeneous preparations with molecular weights of 55, 56, and 57 kD, respectively. The three enzymes were found to be glycoproteins. The carbohydrate moiety of the glycoproteins included mannose, galactose, and N-acetylglucosamine. The carbohydrate moieties of the laccases from C. unicolor 059, C. unicolor 0784, and P. oastreatus 0432 accounted for 17, 23, and 24%, respectively. The pH optima of the enzymes corresponded to 4.0, 3.75, and 5.6, respectively. Thermal stability tests (carried out at 40°C) demonstrated that the laccase of C. unicolor 0784 was characterized by the highest temperature resistance (the enzyme retained 25% activity after 172 h of incubation). The values of the Michaelis constant (K M) were determined for the reactions of oxidation of pyrocatechol, hydroquinone, and potassium ferrocyanide catalyzed by the laccases of the basidiomycetes.
Involvement of β-Carotene in the Antioxidant Defense of the Bacterial Cell by N. N. Gessler; A. V. Sokolov; T. A. Belozerskaya (pp. 382-384).
Effects of recombinant β-carotene on the resistance of E. coli culture to menadione and paraquat were studied. The presence of β-carotene in E. coli cells prevented, to a considerable extent, an increase in superoxide dismutase activity (induced by redox mediators) without affecting the culture growth. These findings suggest that β-carotene is involved in the defense of cells against oxidative stress.
Dependence of Vitamin Content in Saccharomyces Yeasts on the Composition of Nutrient Media by Sh. A. Abramov; S. Ts. Kotenko; A. Sh. Ramazanov; F. I. Islamova (pp. 385-387).
The qualitative and quantitative composition of water-soluble B group vitamins in Saccharomyces yeasts cultivated on various nutrient media was studied by high-performance liquid chromatography. New strains of Saccharomyces oviformis Y-2635 and Saccharomyces vini F-5, grown in a nutrient medium with geothermal water, are characterized by increased biological value due to high intracellular concentrations of riboflavin, LB, nicotinic acid, and folic acid.
Phytotoxic Activities of Chernozem Saprotrophic Micromycetes: Specificity, Sorption, and Stability of Phytotoxins in Soil by I. D. Svistova; A. P. Shcherbakov; L. O. Frolova (pp. 388-392).
Micromycetes of the complex of typical chernozem saprotrophic fungi released phytotoxic metabolites into their growth medium. The metabolites displayed their phytotoxic activities directly in soil. Evaluation of the toxicity, range of biological effects, activity, and stability of the phytotoxins in soil, as well as of the rates of their biodegradation, made it possible to select species that can serve as indicators of microbial toxicosis of chernozem (Aspergillus clavatus, Fusarium solani, Talaromyces flavus, Penicillium rubrum, and P. funiculosum).
Penicillium aurantiogriseum Dierckx 1901: Producer of Diketopiperazine Alkaloids (Roquefortine and 3,12-Dihydroroquefortine), Isolated from Permafrost by A. G. Kozlovsky; V. P. Zhelifonova; V. M. Adanin; T. V. Antipova; S. M. Ozerskaya; N. E. Ivanushkina; U. Grafe (pp. 393-397).
Secondary metabolites of three strains of Penicillium aurantiogriseumisolated from permafrost sediments were identified. It was found that these fungi synthesized the diketopiperazine alkaloids roquefortine and 3,12-dihydroroquefortine. The strain VKM FW-766 synthesized alkaloids in the course of certain growth-related processes. When the strain was grown on a mineral medium, the time courses of the roquefortine and 3,12-dihydroroquefortine concentrations were characterized by biphasic curves.
Determination of the Primary and Fine Structures of a Galactomannan from the Seed of Gleditsia triacanthos f. inermis L. by A. V. Egorov; N. M. Mestechkina; V. D. Shcherbukhin (pp. 398-402).
Galactomannan, a polysaccharide with a molecular weight of 660 kDa, was isolated for the first time from the seed of Gleditsia triacanthos f. inermis (yield, 15.4%). Its aqueous solutions were optically active ([α] D = +31.0°) and highly viscous ([η] = 578 ml/g). Analysis of this heteropolysaccharide using chemical, enzymatic, and chromatographic procedures, as well as IR and 13C NMR spectroscopy, showed that it consists of D-mannopyranose and D-galactopyranose residues (molar ratio, 2.42 : 1). The main chain of this galactomannan comprises 1,4-β-D-mannopyranose residues, 41% of which are substituted at C6 with single residues of α-D-galactopyranose. The probability of occurrence in the chain of mannobiose units substituted otherwise, determined experimentally, was 0.16 for the Man–Man unit, 0.50 for the Gal(Man–Man) and (Man–Man)Gal units, and 0.34 for the disubstituted Gal(Man–Man)Gal unit.
Production of Alkaloids by Fungi of the Genus PenicilliumGrown on Wheat Grain by N. G. Vinokurova; L. V. Boichenko; M. U. Arinbasarov (pp. 403-406).
The ability to produce alkaloids has been studied in 13 strains belonging to ten species of the genus Penicillium. Most of these strains produce identical ranges of alkaloids when grown on wheat grain and synthetic Abe's medium. These are roquefortine, 3,12-dihydroroquefortine, and glandicolines A and B in strain P. chrysogenum VKM F-1987; fumigaclavines A and B, festuclavine, and pyroclavine in P. commune VKM F-308, F-3491, and KBP4; agroclavine 1 and epoxyagroclavine 1 in P. fellutanum VKM F-1073; fellutanine A in P. fellutanum F-3020; roquefortine, 3,12-dihydroroquefortine, meleagrin, and glandicolines A and B in P. glandicola VKM F-743; aurantioclavine in P. nalgiovense VKM F-229; isofumigaclavines A and B, festuclavine, roquefortine, and 3,12-dihydroroquefortine in P. roquefortii VKM F-2389; roquefortine, 3,12-dihydroroquefortine, and meleagrin in P. vitale VKM F-3624; roquefortine and oxaline in P. vulpinum VKM F-256; and α-cyclopiazonic acid and rugulovasine B in P. viridicatum C-47. No alkaloids were found in P. rugulosum VKM F-352 grown on wheat grain. A simple method is proposed for isolating alkaloids from affected grain.
Changes in the Content of 1-Aminocyclopropane-1-carboxylic Acid, Activity of the Protein Polygalacturonase Inhibitor, and Intensity of Oligouronide Formation in Apples during Ripening and Treatment with Haloethane Derivatives or L-α-(2-Aminoethoxyvinyl)-glycine by E. A. Bulantseva; E. M. Glinka; M. A. Protsenko; E. G. Sal'kova (pp. 407-410).
We studied changes in the intensity of ethylene release and accumulation of 1-aminocyclopropane-1-carboxylic acid during ripening of two apple cultivars, differing in their physiological state, following treatment with haloethane derivatives or L-α-(2-aminoethoxyvinyl)-glycine. This changed both the activity of the protein polygalacturonase inhibitor in the fruit tissue and the accumulation of oligouronides. The data suggest that pretreatment with an inhibitor of 1-aminocyclopropane-1-carboxylic acid synthase affects ethylene release, accumulation of 1-aminocyclopropane-1-carboxylic acid, the activity of the protein polygalacturonase inhibitor, and the potential intensity of oligouronide formation in apple fruits and tissues.
Effect of 6-Benzylaminopurine on the Structure of the Photosynthetic Apparatus of Faba Bean (Vicia faba L.) by E. S. Ron'zhina (pp. 411-417).
The level of endogenous cytokinins changed with growth and development of faba bean (Vicia faba L.) leaves. Typical of juvenile leaves, amounting to 25% of the final leaf size (S max), was a low content of these plant hormones. The level of cytokinins increased in growing leaves (50% of S max) and decreased in leaves that stopped growing. The content of cytokinins in senescent leaves dropped considerably. Exogenous treatment with 6-benzylaminopurine (BAP) had no effect on the structure of the terminal phloem; however, it did (1) stimulate elongation of mesophyll cells; (2) increase the area and thickness of the leaf blade, amount of photosynthetic pigments, and assimilation potential; and (3) delay senescence of the leaves and defoliation, thereby increasing the biomass of the aboveground plant part. It is inferred that BAP has the potential for inducing the development of photosynthetic apparatus and increasing the yield of the green mass of faba bean.
Aggregating Ability of Seed Storage Proteins from Cereals Differing in Gluten Quality by V. A. Trufanov; M. D. Permyakova; E. V. Berezovskaya (pp. 418-421).
The effects of medium pH, ionic strength, and composition on the formation of macrocomplexes of seed storage proteins from wheat, rye, and barley have been studied. Various noncovalent interactions (electrostatic and hydrophobic interactions and hydrogen bonds) are involved in protein aggregation. Their combined action depends significantly on the biochemical nature of the storage proteins and on the medium.
New Possibilities for Biospecific Chromatography by I. L. Valuev; L. I. Valuev; N. A. Platé (pp. 422-425).
Polyacrylamide hydrogels covalently modified with duck eggwhite ovomucoid were synthesized by radical copolymerization. These hydrogels can protect insulin (physically immobilized therein) against the action of proteolytic enzymes. Biospecific interaction of the polysaccharide component of the ovomucoid with lectins targets the hydrogel particles to the wall of the small intestine.
Collagen Fractions Obtained by Water–Salt Extraction from Raw Materials of Animal Origin by A. D. Neklyudov; A. V. Berdutina; A. N. Ivankin; S. I. Mitaleva; E. A. Evstaf'eva (pp. 426-430).
Collagen fractions have been isolated by water–salt extraction from raw materials of animal origin (various tendon types or subcutaneous tissues of cattle or porcine skin). Collagen fractions with maximum capacity for water and fat retention were isolated with high efficiency by water–salt solutions containing 1–10% sodium chloride at temperatures below 50°C. The values of the effective constant of extraction rate (min–1) at pH 6.5, 9.0, and 12.0 were equal to (2.7 ± 0.1) × 10–3, (6.2 ± 0.5) × 10–3, and (15.4 ± 0.7) × 10–3, respectively. The optimum conditions found made it possible to isolate from collagen those proteinaceous fractions that are of practical use in food industry.
Protein Hydrolysates Extracted Electrochemically from Crustaceans as Major Components of Nutrient Media by G. G. Nyanikova; E. E. Kuprina; S. V. Vodolazhskaya (pp. 431-434).
The utility of protein hydrolysates extracted electrochemically from crustaceans (Gammarus pulex and shrimp) as major components of microbiological nutrient media was demonstrated. Saprophytic soil bacteria of the genera Bacillus and Pseudomonas and the family Enterobactericeae displayed good growth and typical colony morphology on the experimental media in question.