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Applied Biochemistry and Microbiology (v.38, #5)
Biochemical Processing of Fats and Oils As a Means of Obtaining Lipid Products with Improved Biological and Physicochemical Properties: A Review by A. D. Neklyudov; A. N. Ivankin (pp. 399-409).
Recent advances in the improvement of biological and physicochemical characteristics of lipids are reviewed, with emphasis on products of biochemical processing of natural (animal or plant) fats and oils. Possible uses of these new lipid products include their use in food and forage industries, as well as in the production of new medicines and in biotechnology. Specific features of biochemical transformations of lipids (hydrolysis, esterification, and reesterification) in the presence of water-soluble and immobilized lipases of animal, plant, and microbial origin are scrutinized.
Effects of Antioxidants on Regeneration of Protoplasts of the Filamentous Fungus Trichoderma reesei6/16 by O. V. Cherednichenko; E. A. Zvereva; K. B. Shumaev; Yu. P. Kozlov; M. L. Rabinovich (pp. 410-412).
The relative content of antioxidants in the mycelium of Trichoderma reesei 6/16 obtained by propagation of fungal protoplasts was shown to decrease (as compared to the initial culture taken for preparation of protoplasts) and restored only in the second generation of regenerated mycelium. In this respect, the effects of various antioxidants (β-carotene, ascorbic acid, α-tocopherol, and ionol) on the frequency of regeneration of T. reesei 6/16 protoplasts were studied. β-Carotene increased the viability of fungal protoplasts to the greatest extent. The effect of ascorbic acid depended on the presence of Fe ions. Ionol did not cause any measurable protective effect.
Hydrolysis of Chitosan Sulfate with an Enzyme Complex from Streptomyces kurssanovii by G. E. Bannikova; P. P. Sukhanova; G. A. Vikhoreva; V. P. Varlamov; L. S. Gal'braikh (pp. 413-415).
The possibility of enzymatic hydrolysis of chitosan was shown. The optimum conditions for the process are sodium acetate buffer pH 6.0, 37°C, 24 h, and a chitosan sulfate–protein volume ratio of 500 : 1 in the enzyme preparation. During hydrolysis, the intrinsic viscosity of chitosan sulfate solution decreased by a factor of 2.7.
Separation of Endo-1,4-β-xylanases from Geotrichum candidum3C with Various Abilities to Sorb on Insoluble Substrate by N. A. Rodionova; N. V. Dubovaya; T. I. Odintsova; I. M. Gracheva; A. M. Bezborodov (pp. 416-419).
Culture liquid from Geotrichum candidum 3C was shown to contain three endoxylanase types: endoxylanase I that binds to cellulose, endoxylanase II that sorbs to insoluble xylan, and endoxylanase III that cannot sorb to insoluble substrate. The catalytic and substrate-binding domains of endoxylanase II were isolated.
Cloning of Penicillium canescens Endo-1,4-β-xylanase Gene and Construction of Multicopy Strains by V. A. Serebryanyi; E. A. Vavilova; A. M. Chulkin; Yu. P. Vinetskii (pp. 420-426).
The complete gene xylA that encodes endo-1,4-β-xylanase secreted byPenicillium canescens was cloned and sequenced. The coding region of the gene is separated by eight introns. The protein comprises 302 amino acids of the mature protein and 25 amino acids of the signal peptide. The xylanase of P. canescens belongs to the glycosyl hydrolase family 10. Nucleotide sequences for binding catabolite repression protein CREA and transactivator protein were detected in the promoter region. A set of multicopy strains displaying a seven to eightfold increase in xylanase yield was obtained. The fraction of xylanase in most productive strains amounted to 30–50% of the total secreted protein.
Selection of a Potent Bacillus licheniformis Strain Producing Thermostable Amylase by N. V. Tsurikova; L. I. Nefedova; E. V. Kostyleva; V. I. Zvenigorodskii; V. G. Yasinovskii; T. A. Voeikova; A. P. Sinitsyn (pp. 427-432).
A highly potent strain of Bacillus licheniformis 103 that synthesized thermostable α-amylase with temperature and pH optima of 90–95°C and 6.0–8.5, respectively, was obtained by mutagenesis and selection. The composition of fermentation media and conditions for submerged cultivation of the producer were optimized. α-Amylase whose activity reached 260 U/ml was obtained in laboratory fermenters.
Study of the Oil-Degrading Activity of Caspian Shore Microflora by A. N. Shkidchenko; M. U. Arinbasarov (pp. 433-436).
Soil samples from the shore of Baku Bay (Caspian Sea) were studied. The content of oil products in the samples amounted to 2.7–8.0 wt %. The total counts of microorganisms were 1.8 × 106 cells per g soil, which is by two orders of magnitude lower compared to soils free from oil pollution. In addition, the diversity of microflora is considerably narrower. The samples were used to isolate pure cultures of microbial degraders capable of assimilating 24 to 32% of the oil introduced into liquid nutrient medium in six days. It was demonstrated that the fraction composition of residual oil changed and both light and heavy oil fractions were degraded.
Selection of Microorganisms Capable of Degrading Petroleum and Its Products at Low Temperatures by N. I. Belousova; L. M. Baryshnikova; A. N. Shkidchenko (pp. 437-440).
Of 150 cultures capable of degrading petroleum at +6°C, 40 strains growing in a liquid mineral nutrient medium containing petroleum (2%) as the sole source of carbon were selected. Of them, 13 cultures displaying a petroleum degradation rate exceeding 25% were selected. Abilities of these cultures and their associations to utilize fuel oil and its components—oils and benzene resins—were studied. A culture exhibiting degradation rates of fuel oil, its oils, benzene resins, and petroleum amounting to 17, 26, 10, and 51%, respectively, was selected. This culture can be used for cleanup of petroleum pollution under cold climatic conditions.
Effect of Shale Kerogen Oxidation Products on Biodegradation of Oil and Oil Products in Soil and Water by G. G. Yagafarova; A. Kh. Safarov; E. G. Il'ina; I. R. Yagafarov; V. B. Barakhnina; M. E. Sukharevich (pp. 441-444).
The effect of oxidation products of shale kerogen (high-molecular-weight acids with 6–22 carbon atoms) on biodegradation of oil and oil products in soil and water was studied. High-molecular-weight acids (HMWA) not only affected the layer of oil and/or oil products and dispersed it into small particles, but also stimulated growth of Rhodococcus erythropolis VKM AS-1339D, degraders of oil and oil products. Addition of 0.001–0.003% HMWA to a medium to be purified from oil products increased the extent of bacterial biodegradation by a factor of 1.1–5.0.
Studies of the Stability of Microbial Association Use in Industrial Biofiltering of Gaseous Discharges by A. Yu. Vinarov; Z. N. Robysheva; V. N. Smirnov; D. P. Sokolov (pp. 445-449).
Results of industrial exploitation of a biofiltration plant tailored for purifying gaseous discharges of hazardous organic components such as toluene, cyclohexane, and xylene, are examined. Both numerical and compositional variations were monitored for a long-term (more than 1.5 years) utilization process in an association of microorganisms decomposing organic pollutants. A population of microbial association composed by one yeast and two bacterial strains in the biofilm on the surface of filtering sheets was abundant (108–109 yeast cells/cm2 and 1010–1011 bacterial cells/cm2) and stable during the whole period of monitoring. A microbial association in the culture medium averaging 106 yeast cells/l and 108 bacterial cells/l is more susceptible to technogenic impacts and seasonal fluctuations. Overall, the biofilter as an open and autonomic system maintained its microbial association, thereby providing high-degree (93–98%) purification of industrial gaseous discharges from organic pollutants.
Wood Lignin Modification by the Fungus Panus tigrinus by V. V. Revin; D. A. Kadimaliev; V. V. Shutova; V. D. Samuilov (pp. 450-453).
The treatment of sawdust with the fungus Panus tigrinus VKM F-3616 D changed the contents of functional groups in lignin from wood raw material. These changes are accompanied by the release of carboxyl and phenyl hydroxyl groups involved in chemical bond formation between wood particles in pressed materials manufactured from wood wastes.
Consumption of Triazine Herbicide Atrazine by Laccase-positive and Laccase-negative Strains of Soil Fungus Mycelia sterilia INBI 2-26 by L. G. Vasil'chenko; V. V. Khromonygina; O. V. Koroleva; E. O. Landesman; V. V. Gaponenko; T. A. Kovaleva; Yu. P. Kozlov; M. L. Rabinovich (pp. 454-459).
Asporogenic fungus Mycelia sterilia INBI 2-26 isolated from tropical soils with high residual dioxin content (as a result of Agent Orange defoliant treatment during the Vietnamese–American war) and capable of atrazine decomposition was treated to obtain protoplasts. This technique resulted in isolation of laccase-positive and laccase-negative clones. Atrazine consumption by liquid surface cultures of Mycelia sterilia INBI 2-26 was monitored by using enzyme immune assay and reversed-phase HPLC. Atrazine (20 μg/ml) stimulated fungal growth. The laccase-positive clone consumed up to 80% of atrazine within four weeks. However, no correlation of atrazine consumption and laccase activity in the culture medium was observed. Moreover, the laccase-negative clone was also capable of consuming at least 60–70% of atrazine within three weeks. Surprisingly, in the corresponding control set (cultivation of laccase-negative clone without atrazine) an unidentified metabolite having a retention time and UV-spectrum similar to those of atrazine was also found. It was concluded that the presence of laccase was not a crucial factor in atrazine consumption by this fungus.
Specific Features of Accumulation Kinetics of Entomocidal Exotoxins of Bacillus thuringiensis Subsp. thuringiensisduring the Fermentation Stage of Bitoxibacillin Production by E. I. Efimtsev; G. P. Burov; O. E. Voronina (pp. 460-466).
Accumulation of Bacillus thuringiensis subsp. thuringiensis β-exotoxin (BET) in the course of industrial fermentation (a stage in the production of the entomocidal biopreparation bitoxibacillin) has been studied. It has been demonstrated in model experiments that the decrease in the content of BET in the culture fluid is accounted for by the toxin interaction with an attendant product, the exogenous metabolite (EM). EM has been isolated from the culture fluid and characterized. EM causes alkalization of the medium, exerts entomocidal effects (in Musca domestica), and fails to form salts on treatment with BaCl2. The absorption spectrum of EM is similar to that of BET, showing a maximum at λ = 259 nm. The light-absorbing chromophore is a pyrimidine or purine base. A method for quantitative determination of both exotoxins (BET and EM) in bacterial preparations has been developed.
Localization of Acetyl Groups in the Macromolecule of Glucomannan Obtained from Roots of Eremurus zangezuricus by N. I. Smirnova; N. M. Mestechkina; V. D. Shcherbukhin (pp. 467-469).
Water-soluble glucomannan from roots of Eremurus zangezuricus Mikheev was studied. The polysaccharide contains D-glucose, D-mannose, and acetyl groups in the molecular ratio of 1 : 2.8 : 0.38. 13C NMR studies showed that the polysaccharide under study is a linear, partly acetylated 1,4-β-D-glucomannan. The acetyl groups are attached to the C2 and C3 of mannopyranose units. The polymer contains, on average, one acetyl group per seven mannose units. The glucomannan of E. zangezuricus has the following parameters: [α]D = –37.5°, [η] = 3.73 dl/g, and Mw = 151 kDa.
Induction of Resistance to Phytophthora in Tubers of Transgenic Potato by O. L. Ozeretskovskaya; N. I. Vasyukova; G. I. Tshalenko; N. G. Gerasimova; A. N. Grishanina; L. Ya. Khromova; G. A. Yakovleva; V. P. Varlamov; K. G. Skryabin (pp. 470-473).
Resistance of transgenic cultivars based on the expression of one or more resistance genes is sooner or later broken by pathogens whose race-producing rates are high. Thus, combining transgenesis with elicitor-induced resistance is a promising approach. The elicitor-induced resistance is based on the expression of multiple resistance genes, which can prevent the adaptation of pathogens to transgenic cultivars, maintain the stability of cultivars, and increase their lifespan. In this work, we used transgenic potato cultivars Temp and Superior transformed with Bacillus thuringiensis Δ-endotoxin gene and Luk'yanovskii transformed with leukocyte interferon gene. Arachidonic acid (10–8 M) and soluble chitosan (5 kDa, 100 μg/ml) were used as elicitors for tuber treatment. Our data showed that pretreatment with elicitors causes a 15–25% increase in both the systemic prolonged resistance of potato tubers to Phytophthora infestansand their ability to repair mechanical damage.
Change in the Biochemical Composition of Amaranth Leaves during Selection for Increased Amaranthine Content by M. S. Gins; V. K. Gins; P. F. Kononkov (pp. 474-479).
The composition and content of secondary compounds produced by the shikimate pathway and the contents of protein and cellulose were determined in leaves of amaranth (Amaranthus tricolor L.) K-99 and the cultivar Valentina raised from it by family selection and enriched in the pigment amaranthine. It was found that intense biosynthesis of amaranthine, tyrosine, and phenylalanine resulted in a decrease in the contents of lignin, protein, and cellulose in leaves of Valentina by comparison with K-99 and in changes to the morphological traits: color deepening and a decrease in leaf density. It is concluded that amaranth biosynthesis is related to nitrogen metabolism and amaranthine is an intermediate involved in conversion of nitrogen compounds in the cell.
Sorption of Monoterpenoids and Sesquiterpenoids by Natural Polysaccharides by T. A. Misharina (pp. 480-486).
Sorption of terpenoids (essential oil components) from aqueous solutions by six types of native food starches was studied by capillary gas chromatography. Sorption of volatile substances did not depend on amylose content in starch and specific surface of its granules. The degree of sorption was maximum (86%) for corn starch containing 25–28% amylose and decreased in the following order: tapioca starch (77%) > potato starch (74%) > wheat starch (70%) > high-amylose corn starch (58%) > amylopectin corn starch (57%). Amylopectin corn starch differed from other starches in the mechanism of sorption and selectivity to compounds with various functional groups.
Comparative Characterization of Immune Reagents Based on Hemiacetals of Aflatoxin B1 and Sterigmatocystine by G. P. Kononenko; A. A. Burkin; N. A. Soboleva (pp. 487-492).
Aflatoxin B1 and sterigmatocystine hemiacetal derivatives were synthesized, and their conjugation to albumins and gelatin and also spectral and immunochemical characteristics of reaction products were studied. Data on the specificity and analytical properties of the antibodies produced by immunization with conjugated antigens are given. The possible mechanism of hemiacetal interaction with proteins is discussed. Based on immune reagents to sterigmatocystine hemiacetal, a test system was developed for determination of sterigmatocystine at the sensitivity of 0.1 ng/ml.
Development of Quantitative Enzyme Immunoassay and Radioimmunoassay of λ-Free Light Chains of Immunoglobulins by N. V. Piven'; A. V. Goncharik; Yu. P. Reznikov; G. A. Shkumatova; A. I. Kul'bakova (pp. 493-499).
New quantitative techniques of radioimmunoassay (RIA) and enzyme immunoassay (EIA) were developed for determination of free light λ-chains of immunoglobulins (immunometric sandwich-like variants) in biological fluids using two types of monoclonal specific antibodies (MAB-1 and MAB-2) to different epitopes of the antigen molecule: MAB-1 were immobilized on a solid phase (polystyrene beads), whereas MAB-2 were labeled with iodine or with the enzyme. The test systems prepared can be used for determination of concentrations from 25 to 1000 ng/ml, are very sensitive (25 ng/ml), and the analysis time is 5 h. The two methods were compared, and their clinical and diagnostic validity was evaluated in patients with various diseases associated with disorders in the antibody synthesis by the immune system.
A Reactor-Type Biosensor Based on Rhodococcus erythropolis HL PM-1 Cells for Detecting 2,4-Dinitrophenol by A. E. Kitova; T. N. Kuvichkina; P. V. Il'yasov; A. Yu. Arinbasarova; A. N. Reshetilov (pp. 500-505).
A model of a reactor-type biosensor based on the Rhodococcus erythropolis HL PM-1 was developed for amperometric detection of 2,4-dinitrophenol (2,4-DNP). The effects of the matrix material (agar and calcium alginate gels, ceramic support, and cellulose powder) on the biosensor signal concentration dependence, detection time, and biosensor stability were studied. In the case of bacterial cells immobilized on cellulose powder, the lower limit of 2,4-DNP detection was 20 μM and the time of single analysis, the biosensor recovery included, was 30–50 min. In the continuous detection mode, the biosensor response was maintained at a stable level without biosensor inactivation for ten days. The biosensor can be used as an element of a complex analytical system for detecting nitroaromatic compounds in samples.