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Applied Biochemistry and Microbiology (v.40, #1)
Fungal Decomposition of Natural Aromatic Structures and Xenobiotics: A Review by M. L. Rabinovich; A. V. Bolobova; L. G. Vasil'chenko (pp. 1-17).
The review deals with transformation of natural and synthetic aromatic compounds by fungi (causative agents of white rot, brown rot, and soft rot, as well as soil filamentous fungi). Major enzyme types involved in the transformation of lignin and aromatic xenobiotics are discussed, with emphasis on activity regulation under the conditions of secondary metabolism and oxidative stress. Coupling of systems degrading polysaccharides and lignin and non-phenolic lignin structures (without the involvement of lignin peroxidase) is analyzed, together with nonenzymatic mechanisms involving lipoperoxide free radicals, cation radicals, quinoid mediators, or transition metal ions. Metabolic pathways resulting in the formation of aromatic and haloaromatic compounds in fungi are described. Consideration is given to the mechanisms of fungal adaptation to aromatic xenobiotics.
Effect of Deuteration on the Activity of Methanol Dehydrogenase from Methylophilus sp. B-7741 by A. B. Pshenichnikova; A. N. S. Nevo; E. V. Volkova; D. A. Skladnev; V. I. Shvets (pp. 18-21).
We studied the effect of deuterium oxide present in the medium on the activity of methanol dehydrogenase (EC 1.1.99.8) from methylotrophic bacteria Methylophilus sp. B-7741. Methanol dehydrogenase activity in extracts of the biomass obtained in a highly deuterated medium (2H-enzyme) was 34–47% of the enzyme activity in the control biomass (1H-enzyme), which depended on the reaction conditions. The isotopic effects of substrate deuterium (methanol) for 1H-enzyme and 2H-enzyme were 1.37 ± 0.05 and 1.38 ± 0.01, respectively. We revealed for the first time the reverse isotopic effect of solvent deuterium in the reaction catalyzed by methanol dehydrogenase (0.80 ± 0.02 and 0.60 ± 0.01 for 1H-enzyme and 2H-enzyme, respectively).
Separation of Albumin–Ribonuclease Conjugates by E. A. Zelepuga; N. B. Katushkina; B. M. Kolikov (pp. 22-24).
A method for separation of albumin–ribonuclease (RNase) conjugates has been proposed based on the use of macroporous silicates. It was established that about 76% of ligand-free human serum albumin (LFHSA) formed complexes with enzymes. It was shown that most of the conjugates of albumin and pancreatic RNase contained up to 2 mol enzyme per 1 mol LFHSA. The conjugates of albumin and bacterial RNase isolated from cells of the strain Bacillus intermedius 7P displayed higher specific activities, containing, on average, 2.3 mol RNase per 1 mol LFHSA (for the conjugates with molecular weights below 92 kDa) or 3.3 mol RNase per 1 mol protein carrier (for the conjugates with higher molecular weight).
Production of Penicillium funiculosum 433 Glucose Oxidase and Its Properties by M. V. Sukhacheva; M. E. Davydova; A. I. Netrusov (pp. 25-29).
A method for isolation of extracellular glucose oxidase from Penicillium funiculosum 433 and its purification is proposed. The enzymatic preparation was produced with a yield of 56% and a specific activity of 3730 AU per 1 mg protein. The enzyme studied displayed a high thermostability, resistance to metal ions, and performance in a wide pH range and was equal in its properties to foreign analogues.
Proteinases from Gastric Mucosa of European Sheatfish, Silirus Glanis L. by N. N. Ulitina; M. T. Proskuryakov (pp. 30-34).
Three proteinases (P1, P2, and P3) were isolated from the gastric mucosa of European sheatfish (Silurus glanis L.) by (NH4)2SO4 precipitation, gel chromatography on Sephadex G-75, and ion-exchange chromatography on DEAE cellulose. Isoelectric focusing was used for determining the values of pI of the isolated proteinases, which were equal to 1.9, 3.2, and 4.75 (for P1, P2, and P3, respectively). The molecular weight of P1 was 39800 Da; P2 and P3 had equal molecular weights of 30200 Da each. The optimum pH for the three peptidases isolated from sheatfish gastric mucosa and the maximum stability of these enzymes were found to be at acidic pH. This allowed identification of these proteinases as pepsin-type enzymes of fish.
Enzymatic Hydrolysis of α-Chitin by A. V. Il'ina; O. Yu. Zueva; S. A. Lopatin; V. P. Varlamov (pp. 35-38).
It is shown that the enzymatic preparation Celloviridin G20x can be used for hydrolyzing α-chitin of various origin. The purity of the final product of hydrolysis, N-acetylglucosamine, was monitored using HPLC.
Isolation of Chitin and Chitosan from Honeybees by S. V. Nemtsev; O. Yu. Zueva; M. R. Khismatullin; A. I. Albulov; V. P. Varlamov (pp. 39-43).
A procedure of isolation of chitin, chitosan, and water-soluble low-molecular-weight chitosan from the corpses of bees has been developed. This procedure includes deproteinization of bee corpses, discoloration of the chitin–melanin complex, deacetylation, and enzymatic hydrolysis of chitosan.
Degradation of a Lignin–Carbohydrate Substrate by Soil Fungi Producing Laccase and Cellobiose Dehydrogenase by L. G. Vasil'chenko; K. N. Karapetyan; S. N. Yachkova; E. S. Zernova; M. L. Rabinovich (pp. 44-49).
The growth of nonsporulating mycelial fungi INBI 2-26(+), a producer of laccase; INBI 2-26(–), a producer of cellobiose dehydrogenase; and their mixed culture on lignin–carbohydrate substrates under conditions of submerged fermentation was studied. The degrees of degradation of lignin, cellulose, and hemicellulose of cut straw over 23 days amounted to 29.8, 51.4, and 72% for the laccase producer; 15.8, 33.9, and 59.1% for the cellobiose dehydrogenase producer; and 15.8, 39.4, and 64.5% for the mixed culture, respectively. The laccase activity in the medium when strain 2-26(+) was cultivated individually reached its maximum on day 28; the activity of cellobiose dehydrogenase of strain 2-26(–), on days 14–28. A method for determining cellobiose dehydrogenase activity in the presence of laccase was developed. In the mixed culture, both enzymes were formed; however, the level of laccase synthesis was 1.5-fold lower compared to that of strain 2-26(+), while synthesis of cellobiose dehydrogenase was similar to that of the corresponding producer. Cellobiose dehydrogenase failed to boost the action of laccase while degrading the lignin of straw.
Use of the Fungus Panus tigrinus in the Manufacture of Pressed Materials from Cotton Plant Waste by D. A. Kadimaliev; V. V. Revin; V. V. Shutova; V. D. Samuilov (pp. 49-52).
Changes in the chemical composition of cotton plant stems used as a substrate for solid-phase cultivation of the fungus Panus tigrinus were studied, as well as the effect of these changes on properties of pressed materials made of these stems. During the first 3 days of growth, the fungus better consumed cellulose; then, the rate of cellulose consumption was comparable with that of lignin. The intensity and pattern of these changes depended on the age of the inoculum. The rate of cotton plant waste biodegradation was higher when a 3-day-old inoculum was used. Pressed materials made of the raw material treated with a 3-day-old inoculum of P. tigrinus for 2–3 days displayed better characteristics.
Sulfur-Metabolizing Enzymes in Thermoacidophilic Bacteria Sulfobacillus sibiricus by E. N. Krasil'nikova; T. I. Bogdanova; L. M. Zakharchuk; I. A. Tsaplina (pp. 53-56).
Sulfur oxygenase, sulfite oxidase, adenylyl sulfate reductase, rhodanase, sulfur : Fe(III) oxidoreductase, and sulfite : Fe(III) oxidoreductase were found in cells of aerobic thermoacidophilic bacteria Sulfobacillus sibiricus, strains N1 and SSO. Enzyme activity was revealed in the cells grown on medium with elemental sulfur or in the presence of various sulfide minerals and concentrates of sulfide ores. The activity of enzymes of sulfur metabolism depended little on the degree of aeration during bacterial growth.
Specific Features of Phosphate Transformation on Rhodobacter sphaeroides Chromatophores by N. V. Goncharova; O. G. Kirichenko; L. V. Filatova (pp. 57-59).
ATP production has been shown to take place on illumination of Rhodobacter sphaeroides chromatophores by a single light flash, i.e., in the absence of a proton gradient (which would form as a result of electron transport should a second flash occur). ATP synthesis was accompanied by H2O2 formation. Simultaneous formation of ATP and H2O2 is indicative of oxidative activation of phosphate during ATP synthesis, as in model systems with isolated chlorophyll. These data provide a theoretical background for selecting illumination parameters in laboratory and industrial photobioreactors used for cultivation of photosynthetic bacteria in biotechnological processes.
Microorganisms Degrading Polychlorinated Biphenyls by A. A. Kim; G. V. Pestsov; Kh. T. Yadgarov; G. I. Dzhumaniyazova; P. V. Zinov'ev; G. T. Dzhuraeva; A. A. Abdukarimov; V. K. Gins (pp. 60-62).
Four strains belonging to the genus Bacilluscapable of degrading polychlorinated biphenyls (PCBs) were isolated by screening collection strains of soil bacteria degrading an organochlorine pesticide, hexachlorocyclohexane (HCCH). A method for production of tritium-labeled PCBs was developed. Consumption and degradation of PCBs by the soil bacterial strains selected were studied using tritium-labeled PCBs and GLC. It was demonstrated that PCBs are degradable both in culture media and in model soil samples.
Thermochemical Characterization of the Growth Metabolism of the 2,4-Dichlorophenol-Degrading Strain Pseudomonas GT241-1 by Microcalorimetry by Jun Yao; Yi Liu; Wenhui Zhong; Jing He; Qin Zhou; Xia Qin; Jianping Wang; Songsheng Qu; Ziniu Yu (pp. 63-66).
By using an LKB-2277 Bioactivity Monitor and the ampoule method, the heat output of the growth metabolism of a 2,4-dichlorophenol-degrading bacterial strain, Pseudomonas strain GT241-1, has been determined at 30°C. From the thermogenic curves, it can be established that the thermokinetic equation of their growth metabolism is P t = P t = 0 exp(k m t), dP/dt = k m P 1, with the order of growth metabolism n = 1. The experimental results indicate that the relationship between the metabolic power (P) and the cell concentration (C) and the relationship between the metabolic power of each cell (P 0) and the cell concentration can be characterized by the following thermal equations, respectively: C = a + kP and lnC = a′+k′P 0 or d dC/dP 0 = KC 1. The order of the P 0 –C equation n is also 1. These results are very significant for environmental sciences, biology, and thermochemistry.
Effect of Wild and Genetically Modified Rhizosphere Bacteria Pseudomonas aureofaciens on the Accumulation of Arsenic by Plants by O. I. Sizova; E. V. Lyubun; V. V. Kochetkov; Sh. Z. Validov; A. M. Boronin (pp. 67-70).
Gene constructions rendering recombinant bacteria resistant to arsenic and increasing their ability to dissolve soil phosphates and/or arsenates were created by cloning the ars operon and the gene of citrate synthase from a chromosome of the strain Pseudomonas aeruginosa PA01. Genetically modified variants of the strain Pseudomonas aureofaciens BS1393 have been constructed that are resistant to high concentrations of arsenic and dissolve poorly soluble phosphates and/or arsenates. The recombinant strains P. aureofaciens BS1393(pUCP22::arsRBC) and P. aureofaciens BS1393(pUCP22::gltA) exerted positive effects on the survival of sorgo (Sorghum saccharatum L.) and its ability to accumulate arsenic.
Effect of Alkyl Hydroxybenzenes on Malting Processes by I. Yu. Stepanenko; E. A. Smirnova; E. F. Shanenko; G. I. El'-Registan (pp. 71-75).
It has been shown that one of the alkyl hydroxybenzenes, C7-AHB, can be used in malting for regulating barley growth. Depending on concentration (0.01–1.0%) and duration (from 10 min to 6 h), treatment of barley with a C7-AHB solution stimulates embryo development (0.01–0.02%) or suppresses the growth of vegetative organs (>0.5%) and modulates enzyme activities in germinating grains. Stimulation of the activities of the amylolytic and protein–proteinase complexes in barley depending on the C7-AHB concentration improves malt quality by increasing both the degree of its saccharification and protein dissolution.
Changes in the Activity of Superoxide Dismutase in Rauwolfia serpentina Benth. Callus Cultures Grown under Standard Conditions and Heat Shock by N. V. Kirillova (pp. 76-79).
The rate of superoxide dismutase (SOD) accumulation inRauwolfia serpentinaBenth. cell culture under heat shock conditions (3 h, 45°C) decreased insignificantly (by 4%), whereas low positive temperature (24 h, 7°C) caused a drastic drop (by 48%). The observed decrease in the level of SOD activity resulted from a slowdown of the biosynthesis rate of the enzyme and a decrease in its concentration in the cultivated cells. In addition, a compensatory decrease in degradation of the active protein (K d) was observed at low positive temperatures and, consequently, an increase in its half-life (tt 1/2), compensating partially for a deficiency in de novo synthesized SOD molecules. The parameters studied were restored to normal after a 24-h adaptation of cells under standard temperature conditions.
Isolation of Polysaccharides from the Callus Culture of Lemna minor L. by E. A. Günter; O. V. Popeiko; Yu. S. Ovodov (pp. 80-83).
Two fractions that included acid arabinogalactan and pectin were extracted from the callus culture of duckweed plants (Lemna minorL.) with water and ammonium oxalate. Residues of galactose and arabinose (ratio, (2.0–2.5) : 1) were the major constituents of acid arabinogalactan. The pectin fraction contained primarily residues of glycuronic acids, galactose, and arabinose. The percentages of arabinogalactan and pectin were similar. The yield of polysaccharide fractions did not depend on the method used for their isolation. Extraction with water, treatment of the biomass with aqueous formalin and dilute hydrochloric acid, and extraction with aqueous ammonium oxalate allowed us to obtain the pectin polysaccharide with the highest purity.
Purification and Characterization of Lipase from Wheat (Triticum aestivum L.) Germ by V. S. Kapranchikov; N. A. Zherebtsov; T. N. Popova (pp. 84-88).
A method of isolation and purification of lipase (EC 3.1.1.3) from the germ of wheat (Triticum aestivumL.) is described. An electrophoretically homogeneous preparation of the enzyme (specific activity, 622.5 × 10–3 μmol/min per mg protein) was obtained after 61-fold purification. The molecular weight of the enzyme, determined by gel chromatography, was 143 ± 2 kDa. The optimal conditions for the enzyme were 37°C and pH 8.0. The homogeneous preparation of the lipase exhibited high thermal stability: over 20% of the original activity was retained after incubation of the preparation at high temperatures (60–90°C) for 1 h at pH 8.0.
Role of the Polygalacturonidase Inhibitor Protein in the Ripening of Apples and Their Resistance to Monilia fructigena, a Causative Agent of Fruit Rot by N. L. Buza; A. A. Krinitsyna; M. A. Protsenko; V. V. Vartapetyan (pp. 89-92).
We investigated the dynamics of the activity of the polygalacturonidase inhibitor protein (PGIP) in apple fruits of six cultivars differing in ripening time and correlated it with the degree of damage by the causative agent of fruit rot, Monilia fructigena. The apple cultivars studied differed significantly in PGIP activity and degree of damage by Monilia fructigena. The rate of dissemination of the fungus over fruit tissues was inversely related to PGIP activity. The resistance of apples to M. fructigena increased with ripening. The simultaneous increase in PGIP activity suggests its important role in the reduction of apple damage by fruit rot.
Correlation between the Structure of Plant Steroids and Their Effects on Phytoparasitic Nematodes by Zh. V. Udalova; S. V. Zinov'eva; I. S. Vasil'eva; V. A. Paseshnichenko (pp. 93-97).
The effects of certain plant steroids (belonging to furostanol glycosides or glycoalkaloids) and α-ecdysone on growth and development of phytoparasitic nematodes were studied. It was shown using an experimental system including tomato Lycopersicon esculentum Mill. and root-knot nematode, Meloidogyne incognita Kofoid et White, that a steroid molecule exhibits significant nematicidal activity if it contains a carbohydrate moiety and an additional heterocycle in the steroid core. The maximum nematicidal activity is inherent in glycosides containing chacotriose as the carbohydrate moiety of the molecule. Some compounds tested in this work could be used for protecting plants against phytoparasitic nematodes.
Effect of Heavy Metals on Wheat Seedlings: Activation of Antioxidant Enzymes by S. V. Murzaeva (pp. 98-103).
Accumulation of heavy metals in wheat grain exposed to multicomponent pollutants (industrial wastewater) was studied. The absolute content of metals (Zn, Cd, Cu, Cr, Ni, Co, Pb, and Mn) was found to be determined by the extent of purification of wastewater. An increase in the degree of grain contamination with heavy metals was accompanied by activation of antioxidant enzymes (superoxide dismutase, EC 1.15.1.1; catalase, EC 1.11.1.6; and peroxidase, EC 1.11.1.7) in leaves and activation of superoxide dismutase and peroxidase in roots. The ratio of activity of membrane enzymes to activity of cytosol enzymes was demonstrated to be high. It was concluded that the membranotropic effect of multicomponent contaminants was due to accumulation of heavy metals capable of inducing the antioxidant protection in the next generation of wheat seedlings.
Retention of Essential Oil Components Sorbed by Native Cornstarch during Storage by T. A. Misharina (pp. 104-107).
Changes in the content of essential oil components sorbed by native dry cornstarch during storage were studied by the method of capillary gas chromatography. The composition of volatile substances changed insignificantly, and the sample retained its organoleptic characteristics throughout storage for 3 months. Up to 70–80% of monoterpene hydrocarbons and lower sulfides disappeared after 6 months. The loss of terpene alcohols, acetates, and ketones did not exceed 10%. Storage was accompanied by an increase in the content of essential oil components bound to the surface of starch granules.