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New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
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Applied Biochemistry and Microbiology (v.38, #2)
Antimutagenic Properties of Bacteria: Review by L. I. Vorobjeva; S. K. Abilev (pp. 97-107).
Lactic acid and propionic acid bacteria, bifidobacteria, and fecal enterococci associated with the activity of humans and animals caused antimutagenic effects (AME) on many test systems designed for detecting point mutations and chromosomal aberrations. Bacterial cells and some of their metabolites attenuate the mutagenic action of several genotoxic agents, and this effect is mediated by the mechanism of dysmutagenesis and/or bioantimutagenesis. Possible mechanisms of various AMEs and possible practical applications of antimutagenic properties of bacteria are discussed.
Optimization of Conditions of Preparative Chromatography of Carminomycin on a Carboxylic Cation Exchanger by A. Yu. Toshchevikova; O. A. Pisarev (pp. 108-111).
The time course of equilibrium and nonequilibrium sorption of carminomycin on the carboxylic cation exchanger BDM-12 has been studied. Physicochemical requirements and the limits of the mobile phase flow rate are determined for the regular mode of preparative chromatography under the conditions of sharpening of the chromatographic zone.
Depolymerization of High-Molecular-Weight Chitosan by the Enzyme Preparation Celloviridine G20x by A. V. Il'ina; Yu. V. Tkacheva; V. P. Varlamov (pp. 112-115).
A low-molecular-weight water-soluble chitosan was obtained from high-molecular-weight crab chitosan using the enzyme preparation Celloviridine G20x. Optimum conditions for enzymatic hydrolysis were designed. The reaction should be performed for 4 h in a sodium-acetate buffer (pH 5.2) at 55°C and an enzyme to substrate ratio of 1 : 400. Fractional extraction of chitosan hydrolysate by aqueous ethanol (ethanol:distilled water) yielded fractions with molecular weights in the range 3.2–26.4 kDa.
Bacterial Succession on n-Alkanes under the Conditions of Sulfate Reduction by T. V. Koronelli; T. I. Komarova; L. F. Tkebuchava (pp. 116-119).
The dynamics of species composition of a hydrocarbon-oxidizing bacteriocenosis of a ground suspension of the Mozhaisk Reservoir has been studied. The bacteriocenosis was undergoing development in a paraffin film (model association composed of sulfate-reducing bacteria and hydrocarbon-oxidizing bacteria). The type of bacterial succession did not depend on the depth, from which ground samples were collected. Two microbial species (Pseudomonas sp. andArthrobacter globiformis) were absolutely dominant. Pseudomonas sp. was dominant at the early and intermediate stages of the succession, whereas A. globiformis was present in the hydrocarbon-oxidizing bacteriocenosis throughout the whole period of the succession. There was a trend toward a gradual increase in the ratio of A. globiformis, and, by the end of the experiment, Pseudomonas sp. was replaced by A. globiformis almost completely. The bacterial species Micrococcus sp. and Rhodococcus erythropolis were minor components of the hydrocarbon-oxidizing bacteriocenosis under the conditions of sulfate reduction. The succession of species of hydrocarbon-oxidizing bacteria in the paraffin film of the model association reflects both the life strategy of the bacterial species under study and the degree of their tolerance to products of sulfate reduction.
Entomopathogenic Bacteria Bacillus thuringiensis as Producers of Restriction Endonucleases by L. I. Puchkova; G. V. Kalmykova; L. I. Burtseva; V. E. Repin (pp. 120-124).
A total of 115 collection strains of Bacillus thuringiensis, belonging to various subspecies, have been studied for the presence of DNA restriction–modification systems. Restriction endonucleases of 13 strains have been isolated and characterized. No considerable correlations between the taxonomic positions of the bacteria and the specificities of the endonucleases isolated have been detected. It is concluded that the enzymes with identical specificities are present in both the crystalliferous and acrystalliferous strains of the same subspecies.
Anaerobic Degradation of Biphenyl by the Facultative Anaerobic Strain Citrobacter freundii BS2211 by V. G. Grishchenkov; A. V. Slepen'kin; A. M. Boronin (pp. 125-128).
Using a synthetic medium supplemented with biphenyl (a polycyclic aromatic hydrocarbon), a new bacterial strain of Citrobacter freundiiwas isolated from enrichment cultures containing soil and industrial wastewater samples of the Serpukhov Condenser Factory. This strain was found to be capable of degrading biphenyl under anaerobic conditions in the course of nitrate reduction. When the initial concentration of biphenyl in the culture medium equaled 150 mg/ml, the culture with a titer of 109 cells/ml degraded up to 26–28% of biphenyl in 3 days (28°C). At 250 mg/ml, the culture with a titer of 107 cells/ml degraded 15% of biphenyl in 21 days. Approximately 10% of the substrate consumed was utilized completely, whereas the remainder underwent transformation.
Changes in Lipid Composition and Carbohydrate Composition of Aspergillus niger Conidia during Germination by E. V. Morozova; V. P. Kozlov; V. M. Tereshina; A. S. Memorskaya; E. P. Feofilova (pp. 129-133).
Data on the lipid composition and carbohydrate composition of Aspergillus niger conidia make it possible to characterize the individual germination stages and differentiate between the conidia capable of germination and those that lost the germination capacity. The following criteria are proposed: the ratio of phosphatidylcholine and phosphatidylethanolamine, the ratio of mannitol and arabitol, and the levels of sterols and free fatty acids. The role of these compounds in the biochemical background of cell transition from dormancy to active metabolism and their use as indices of the quality of inocula in biotechnological processes are discussed.
Amylases of the Fungus Aspergillus flavipes Associated with Fucus evanescens by G. M. Frolova; A. S. Sil'chenko; M. V. Pivkin; V. V. Mikhailov (pp. 134-139).
A promising producer of extracellular amylases, Aspergillus flavipes, was selected from 245 strains of marine fungi. Depending on the conditions of growth, this strain produced diverse amylolytic complexes. When grown on a medium containing peptone and yeast extract (pH 7.0), A. flavipes synthesized three forms of amylase, differing in pH optimum (5.5, 6.0, and 7.5). A single form of the enzyme was synthesized either in the absence of peptone from the medium or at the initial pH value of the medium, equal to 8.6. The activity of the isolated amylase forms decreased in the presence of proteolytic enzymes. New, highly stable forms of amylase (with pH optima of 5.5 and 7.5 and maximum activity at 60–80°C) were synthesized in the presence of diisopropyl fluorophosphate, an inhibitor of proteases.
Protein and Peptide Factors from Bacillus sp. 739 Inhibit the Growth of Phytopathogenic Fungi by A. V. Shirokov; O. N. Loginov; A. I. Melent'ev; G. E. Aktuganov (pp. 139-144).
Thermolabile peptides inhibiting the growth of Helminthosporium sativum, a facultative phytopathogen, have been isolated from the low-molecular-weight fraction of extracellular metabolites of the strain Bacillus sp. 739. Paper chromatography of the fraction, followed by bioautography, revealed the presence of three components exhibiting antifungal activity. These components were separated by gel chromatography on Toyopearl HW-40. SDS-Na-PAGE (the Laemmli procedure) demonstrated that only one component was a protein (MW, ∼14 kDa). The other two substances were polypeptides with molecular weights less than 6 kDa each. The protein factor inhibited the growth of H. sativum with a minimum effective concentration of 0.1 to 0.2 mg/ml.
Antimicrobial Activity of Resins Obtained from the Roots and Stems of Cedrus libani and Abies cilicia by Murat Kizil; Göksel Kizil; Murat Yavuz; Çetin Aytekin (pp. 144-146).
The antimicrobial activity of the ethanol extract of resins obtained from the roots and stems of Cedrus libani and Abies cilicia has been studied, using the disc diffusion method. The results obtained indicate that crude extracts of the resins of both plants are highly efficient in preventing the growth of microorganisms.
Antioxidant Activity in Fungi Degrading Lignocellulose Substrates by V. G. Babitskaya; V. V. Shcherba (pp. 147-150).
Considerable differences in lignin degradation by fungi of two ecological groups have been revealed. Xylotrophs cause a twofold decrease in the molecular weight of lignin. The degrading activity of saprotrophs is insignificant. Xylotrophs demethoxylate and oxidize lignin more rapidly than saprotrophs, showing a higher level of antioxidant activity. As follows from the comparison of the degrading and antioxidative effects, measurement of the antioxidant activity can be used in screening of fungi for the ability to degrade lignocellulose substrates.
Stabilization of Diluted Aqueous Solutions of Horseradish Peroxidase by A. N. Eremin; L. P. Budnikova; O. V. Sviridov; D. I. Metelitsa (pp. 151-158).
Effects of pH, enzyme concentration, and various supplements on the catalytic activity, temperature stability, and secondary structure of horseradish peroxidase (HRP) were studied in diluted aqueous solutions. In 5.0 mM citrate-phosphate buffer (pH 4.2) at 55°C and infinite dilution, HRP was inactivated with a rate constant of 2.86 × 10–3 s–1. CaCl2, BSA, and glycerol caused protective effects, whereas KCl, LiCl, maltose, PEG-6000 (at a concentration above 3%), Triton X-100, ethanol, and Kathon CG had an opposite effect and altered the secondary structure of HRP. Two HRP-stabilizing media: the “glycerol-based” one containing 10% ethanol and 20% glycerol, or the “protein-based” one containing 0.1% Kathon CG and 0.2 mg/ml of BSA in 50.0 mM Tris-HCl buffer (pH 7.2) supplemented with 50 mM CaCl2 were developed, and the stability of HRP (0.36 nM) and its immunoglobulin, cortisol, and progesterone conjugates were compared in these two media. The protein-based medium displayed a greater stabilizing effect particularly on HRP-steroid conjugates.
Proteins and Saponins in the Lipid Preparation Obtained by Extraction of Soybean Flour by N. A. Baukova; S. G. Alekseeva; G. M. Sorokoumova; A. A. Selishcheva; O. M. Martynova; E. A. Rogozhkina; V. I. Shvets (pp. 159-164).
A complex lipid preparation was obtained by extracting soybean flour with organic solvents. This preparation was shown to include not only phospholipids (major components), but also 30% saponins. These compounds were identified by TLC, HPLC, and 1H-NMR spectroscopy. Minor components of the lipid extract were represented by polypeptides bound to phospholipids by electrostatic or hydrophobic forces.
Effect of Bacterial Infection on the Lipid Composition of Carp Blood Lymphocytes by V. V. Bogdan; L. P. Smirnov; V. S. Sidorov (pp. 165-168).
The initial stage of bacterial infection is characterized by an increase in the level of total lipids and polyenoic fatty acids in membrane phospholipids of blood lymphocytes of carp (Cyprinus carpio L.). In the fish infected with aeromonads, changes in the ratios of fatty acids in phospholipids are similar for either lymphocytes, liver, or whole blood. The extent to which these changes are pronounced depends on the original physiological status of the fish.
Group-Specific Antibodies against Zearalenone and Its Metabolites and Synthetic Analogs by A. A. Burkin; G. P. Kononenko; N. A. Soboleva (pp. 169-176).
Formation kinetics, specificity, and analytical potential of polyclonal antibodies raised in rabbits against BSA conjugates of zearalanone carboxymethyloxime (CMO-ZAN) and zearalenone carboxymethyloxime (CMO-ZEN) have been studied. Preparation of the conjugates involved conversion of CMO-ZAN and CMO-ZEN into activated esters or carbodiimide condensation. Two versions of a group-specific enzyme immunoassay (for zearalenone/α-zearalenol and zearalanone/α-zearalanol) based on the heterologous combination of solid-phase antigens are described (sensitivity, 0.01 ng/ml).
Effect of Ambiol on Stem Growth in Regenerants of Source and Transgenic Potato Plants by A. S. Evsyunina; N. S. Lyapkova; T. A. Platonova; N. P. Korableva (pp. 177-180).
The effects of ambiol, a new growth regulator, on stem growth and morphological features of stem development have been compared in regenerants of potato (Solanum tuberosum L., var. Desire) plants transgenic for a defensin gene and in original potato plants. The original and transgenic plants exhibited differences in shoot development, which were observed both in control settings (no ambiol) and in the presence of various ambiol concentrations. In addition to normal plants of both forms, plant regenerants with morphological deviations were present in ambiol-treated groups. It is suggested that the abnormal shoot development observed in original and transgenic potato plants treated with ambiol is associated with (a) hormonal changes caused by expression of the defensin gene in the transgenic plants and (b) effects of ambiol on the hormonal balance of the plants.
Changes in Macromolecular Characteristics and Biological Activity of Hydrolytic Lignin in the Course of Composting by L. N. Novikova; S. A. Medvedeva; I. V. Volchatova; S. A. Bogatyreva (pp. 181-185).
Composting of hydrolytic lignin by a microbial association changed its molecular-weight composition, acid-base properties, and supramolecular structure. Specifically, by the end of the third month of composting, an increase was observed in its exchange capacity and the amount of negative charges, as well as in the content of phenyl, hydroxyl, and carboxyl groups. The use of this compost as a fertilizer for barley growth demonstrated that the changes increased the biological activity of hydrolytic lignin.
Contents of Alginic Acid and Fuccidan in Fucus Algae of the Barents Sea by E. D. Obluchinskaya; G. M. Voskoboinikov; V. A. Galynkin (pp. 186-188).
Seasonal changes in the content of alginic acid and fuccidan have been studied in four species of fucus algae from the Barents Sea: Fucus vesiculosus, F. distichus, F. serratus, and Ascophyllum nodosum. These polysaccharides are accumulated in the biomass of the algae during summer and autumn. To ensure complete processing of fucus algae it is recommended that the raw material be harvested within this period.
Utilities of Luminous Bacteria from the Black Sea by A. M. Katsev (pp. 189-192).
Luminous bacteria, isolated from summer specimens of water of the Black Sea, have been identified as strains of Photobacterium phosphoreum and Vibrio fischeri (two of each). Morphological, physiological, and biochemical properties of the four strains have been characterized, and the kinetic behavior of luciferases isolated therefrom has been studied. The sensitivity of the luminescence of the strains to certain toxic agents has been compared to that of the test strain Ph. phosphoreum (Cohn) Ford. The results obtained indicate that the new strains show promise as bioindicators.
Milk Ultrafiltrate as a Promising Source of Angiogenin by T. V. Fedorova; G. S. Komolova; M. A. Rabinovich; N. A. Tikhomirova; A. M. Shalygina (pp. 193-196).
The use of membrane technologies in the production of curd (soft cheese for children) is associated with the appearance of up to 80% of angiogenin in the ultrafiltrate. An electrophoretically homogeneous preparation of angiogenin (MW ∼17 kDa) was obtained from milk ultrafiltrate by two-stage ion-exchange chromatography. The yield of the angiogenin was ∼60%, which corresponds to a 586-fold purification of the raw material. The obtained preparation retained stability in the course of lyophilization and could be stored at 4°C for a long time without decomposition.