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1.
Prikl Biokhim Mikrobiol ; 26(1): 19-25, 1990.
Article in Russian | MEDLINE | ID: mdl-2190207

ABSTRACT

Continuous enzymatic synthesis of L-malic acid from potassium fumarate in packed-bed flow reactors was investigated. Carrageenan-immobilized Escherichia coli cells were used as a biocatalyst. The operational stability of the biocatalyst fumarase activity was studied, and conditions for preserving high activity of the biocatalyst were determined.


Subject(s)
Escherichia coli/metabolism , Fumarate Hydratase/metabolism , Malates/metabolism , Bacteriological Techniques , Carrageenan , Catalysis , Enzyme Stability , Escherichia coli/enzymology , Escherichia coli/growth & development
2.
Article in Russian | MEDLINE | ID: mdl-2192748

ABSTRACT

UNLABELLED: Operations were performed on 750 children with cystic hypoplasia and dysontogenetic and acquired bronchiectases. The operation volume: pulmonectomy, lobectomy, combined resections, resection of pulmonary tissue with extirpation of bronchi, extirpation of bronchi. COMPLICATIONS: atelectasis, pneumonia, intrapleural hemorrhage were encountered in 87 (11.6%) children. Six (0.8%) children died. Recurrent or residual bronchiectases were found in 27 children, 18 underwent a second operation. Recurrences were encountered mainly in children with dysontogenetic bronchiectases.


Subject(s)
Bronchiectasis/surgery , Cystic Adenomatoid Malformation of Lung, Congenital/complications , Bronchi/surgery , Bronchiectasis/etiology , Child , Chronic Disease , Drainage , Humans , Pneumonectomy/methods , Postoperative Care , Preoperative Care , Suture Techniques
3.
Biokhimiia ; 54(12): 1994-9, 1989 Dec.
Article in Russian | MEDLINE | ID: mdl-2699255

ABSTRACT

It was found that the nonspecific effect of ionic strength of the external solution on the enzymatic activity of E. coli cells consists in rapid changes in the permeability of cell membranes interacting with the substrate. This effect depends on the initial substrate concentration, i.e., ionic strength of the external solution, and is maintained for some time as the substrate concentration decreases. Chloramphenicol, a protein synthesis inhibitor, and sodium azide, a respiration inhibitor (300 micrograms/ml and 200 microM, respectively) do not change the enzymatic activity of E. coli cells during the synthesis of L-aspartic and L-malic acids from fumaric acid. The kinetic equations of L-aspartate and L-malate synthesis are described by equations of zero and intermediate (between zero and first) order, respectively.


Subject(s)
Ammonia-Lyases/metabolism , Aspartate Ammonia-Lyase/metabolism , Escherichia coli/enzymology , Fumarate Hydratase/metabolism , Aspartic Acid/metabolism , Azides/pharmacology , Catalysis , Cell Membrane Permeability , Chloramphenicol/pharmacology , Escherichia coli/metabolism , Fumarates/metabolism , Kinetics , Malates/metabolism , Osmolar Concentration , Sodium Azide , Substrate Specificity
4.
Prikl Biokhim Mikrobiol ; 25(2): 278-85, 1989.
Article in Russian | MEDLINE | ID: mdl-2500647

ABSTRACT

A possibility of using the ninhydrin reaction for 3,4-dihydroxyphenyl-L-alanine (DOPA) determining during the synthesis from pyrocatechol and ammonium pyruvate was verified by using free and immobilized cells of Citrobacter freundii, st. 62. Spectrophotometric assay was performed at the adsorption maximum for the DOPA-ninhydrin complex at 390 nm. DOPA can be reliably quantified in the presence of all components at 20-fold and greater dilution of the reaction mixture. A high-sensitive quantitative assay of the reaction mixture was developed based on phase-reversed HPLC. A quantitative correlation was observed between spectrophotometric and chromatographic assays. The assays were employed to study in detail the initial period and equilibrium of DOPA synthesis and its characteristic features, which made it possible to construct a kinetic model of the process.


Subject(s)
Citrobacter/metabolism , Dihydroxyphenylalanine/analysis , Catechols , Chromatography, High Pressure Liquid , Dihydroxyphenylalanine/chemical synthesis , Ethanol , Indicators and Reagents , Ninhydrin , Pyruvates , Pyruvic Acid , Spectrophotometry, Ultraviolet , Spectrum Analysis
5.
Prikl Biokhim Mikrobiol ; 24(3): 400-4, 1988.
Article in Russian | MEDLINE | ID: mdl-3050975

ABSTRACT

Conditions were determined for preparation of spheroplasts from E. coli under the action of lysozyme in the presence of EDTA. The preparation took from 10 to 15 min. The degree of conversion to spheroplasts was monitored spectrophotometrically at 660 nm. The spheroplasts formed were unstable in Tris-HCl buffer and immediately lysed, but they were more stable in 1 M sucrose. At lysozyme concentrations above 40 micrograms/ml of the reaction mixture, the cells lysed to a greater extent. The distribution of aspartate ammonia-lyase activity between the precipitate of the spheroplasts and the supernatant allowed the authors to suggest that aspartase should be located in the cytoplasm.


Subject(s)
Ammonia-Lyases/analysis , Aspartate Ammonia-Lyase/analysis , Escherichia coli/enzymology , Spheroplasts/isolation & purification , Escherichia coli/ultrastructure , Spheroplasts/enzymology
6.
Prikl Biokhim Mikrobiol ; 24(1): 35-41, 1988.
Article in Russian | MEDLINE | ID: mdl-3285339

ABSTRACT

Optimal conditions were chosen for cultivation of Escherichia coli 85 cells with a rather high fumarate-hydratase activity on a cheap medium containing no edible raw material. An active biocatalyst for the synthesis of L-malic acid from fumaric acid was obtained based on E. coli 85 cells immobilized in carrageenan. The enzymatic synthesis of L-malic acid from potassium fumarate was kinetically studied and optimized. Some thermodynamic parameters of fumaric acid hydration into malic acid were determined. A technique for assaying the reaction mixture was developed that involved high performance liquid chromatography.


Subject(s)
Escherichia coli/metabolism , Fumarate Hydratase/metabolism , Fumarates/metabolism , Malates/biosynthesis , Escherichia coli/enzymology , Kinetics
7.
Prikl Biokhim Mikrobiol ; 23(2): 192-8, 1987.
Article in Russian | MEDLINE | ID: mdl-3106951

ABSTRACT

A kinetic study was carried out of the enzymatic synthesis of 3,4-dihydroxyphenyl-L-alanine (DOPA) by the Citrobacter freundii 62 cells, possessing tyrosine-phenol-lyase (TPL) activity, immobilized in carrageenan, and optimum conditions of the reaction were found. The dependence of the TPL activity and its stability on the conditions of the DOPA synthesis was investigated. The TPL activity was higher and more stable in the immobilized cells as compared to free ones.


Subject(s)
Citrobacter/metabolism , Dihydroxyphenylalanine/biosynthesis , Bacteriological Techniques , Carrageenan , Kinetics
8.
Prikl Biokhim Mikrobiol ; 22(4): 507-10, 1986.
Article in Russian | MEDLINE | ID: mdl-3532088

ABSTRACT

The conditions for cultivation of E. coli 85 on a glucose-mineral medium with a yeast extract were optimized. The cells obtained had a high aspartate ammonia-lyase activity. The aspartase activity was determined kinetically both by consumption of the substrate, ammonium fumarate, and by accumulation of the product, aspartic acid.


Subject(s)
Ammonia-Lyases/metabolism , Aspartate Ammonia-Lyase/metabolism , Escherichia coli/enzymology , Culture Media , Escherichia coli/growth & development , Glucose , Minerals , Yeasts
9.
Prikl Biokhim Mikrobiol ; 21(4): 506-9, 1985.
Article in Russian | MEDLINE | ID: mdl-3906630

ABSTRACT

The cells of Escherichia coli 85 immobilized in carrageenan from various sources were being studied for the aspartase activity and stability. These properties of the resultant preparations which display a relatively high and stable biocatalytic activity were shown to be almost independent of the raw material from which carrageenan was obtained and of the degree of its purification.


Subject(s)
Ammonia-Lyases/metabolism , Aspartate Ammonia-Lyase/metabolism , Carrageenan/pharmacology , Escherichia coli/enzymology , Acrylic Resins/pharmacology , Aspartic Acid/biosynthesis , Catalysis , Escherichia coli/drug effects , Gels , Kinetics
10.
Prikl Biokhim Mikrobiol ; 21(3): 334-41, 1985.
Article in Russian | MEDLINE | ID: mdl-3900976

ABSTRACT

The conditions for immobilization of Escherichia coli cells (Soviet strain 85) on the natural polysaccharide carrier carrageenan (Soviet-made) were investigated and kinetic regularities of the aspartase reaction catalysed by immobilized in carrageenan cells of E. coli 85 were established. The conditions for retaining a high aspartase activity and stability of biocatalysts based on the E. coli 85 cells immobilized in PAAG and carrageenan were determined using full-loaded tanks for continuous synthesis of L-aspartic acid. The time-stable aspartase activity of the biocatalyst can be increased by treating the beads of the catalyst with bifunctional reagents (hexamethylenediamine, glutaraldehyde), the most active catalyst for the biotechnological synthesis of L-aspartic acid being obtained when carrageenan is used.


Subject(s)
Acrylic Resins/pharmacology , Ammonia-Lyases/metabolism , Aspartate Ammonia-Lyase/metabolism , Carrageenan/pharmacology , Enzymes, Immobilized/metabolism , Escherichia coli/enzymology , Aspartic Acid/biosynthesis , Catalysis , Drug Stability , Escherichia coli/drug effects , Gels , Kinetics , Temperature
11.
Prikl Biokhim Mikrobiol ; 21(2): 161-6, 1985.
Article in Russian | MEDLINE | ID: mdl-3921951

ABSTRACT

The Citrobacter freundii 62 cells immobilized in PAAG and possessing the tyrosine-phenol-lyase (TPL) activity catalyse the synthesis of 3,4-dihydroxyphenyl-L-alanine (DOPA) from pyrocatechol and ammonium pyruvate. The synthesis of DOPA was studied using both free and immobilized bacterial cells. When the concentration of pyrocatechol is over 0.1 M the TPL activity of the cells is inhibited. The concentration of pyrocatechol can be increased up to 0.3 M by using an equimolar mixture of pyrocatechol and boric acid. The addition of ascorbic acid as an antioxidant results in a lower TPL activity of both free and immobilized bacterial cells.


Subject(s)
Citrobacter/enzymology , Dihydroxyphenylalanine/biosynthesis , Acrylic Resins/pharmacology , Catechols/metabolism , Chromatography, Thin Layer , Citrobacter/drug effects , Dihydroxyphenylalanine/analysis , Gels , Kinetics , Pyruvates/metabolism , Pyruvic Acid , Tyrosine Phenol-Lyase/metabolism
13.
Prikl Biokhim Mikrobiol ; 20(4): 435-44, 1984.
Article in Russian | MEDLINE | ID: mdl-6382244

ABSTRACT

The present review systematizes the literature data on localization of enzymes in cells of Gram-negative bacteria. It centres round the methods used for studying the enzyme localization. The criteria according to which one can locate an enzyme in bacterial cells are discussed.


Subject(s)
Enzymes/isolation & purification , Gram-Negative Bacteria/enzymology , Bacteriological Techniques , Cell Membrane/enzymology , Cell Membrane Permeability/drug effects , Centrifugation , Cytoplasm/enzymology , Gram-Negative Bacteria/drug effects , Histocytochemistry , Macromolecular Substances , Mutation , Osmotic Pressure , Spheroplasts/enzymology
14.
Prikl Biokhim Mikrobiol ; 20(3): 329-33, 1984.
Article in Russian | MEDLINE | ID: mdl-6379637

ABSTRACT

The fumarate hydratase activity of intact cells was determined for 36 strains of Escherichia coli, receiver from the All-Union Collection of Microorganisms, to reveal a producer of L-malic acid. A research was made to find optimal media for cultivating microorganisms possessing the fumarate hydratase activity. Spectrophotometric and chromatographic methods were chosen to detect malic acid in the complete reaction mixture, which are available for kinetic study of the malic acid synthesis from potassium fumarate.


Subject(s)
Escherichia coli/enzymology , Fumarate Hydratase/metabolism , Chromatography, Gel/methods , Chromatography, High Pressure Liquid/methods , Culture Media/metabolism , Escherichia coli/analysis , Fumarate Hydratase/analysis , Kinetics , Malates/analysis , Malates/biosynthesis , Spectrophotometry, Ultraviolet/methods
15.
Radiobiologiia ; 24(2): 269-73, 1984.
Article in Russian | MEDLINE | ID: mdl-6328570

ABSTRACT

Development of tumors in the liver of dogs exposed to gamma-quanta for 3 and 6 years at dose--rates of 0.0006, 0.0017 and 0.0034 Gy/day was studied 1-10 years after termination of the exposure. The results are summarized in this work. Tumors were found in 27 out of 89 dogs. The number of benign and malignant tumors was virtually the same (13 and 14). In the first place were hepatoma, among benign neoplasms (9 out of 13), and liver cancer, among malignant tumors (12 out of 14). Neoplasms were more frequent (32%) in exposed animals than in the controls (19%). Tumors were almost two times more frequent and developed earlier after 6 year- than after-3-year-irradiation.


Subject(s)
Liver Neoplasms/etiology , Neoplasms, Radiation-Induced/etiology , Animals , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/pathology , Dogs , Dose-Response Relationship, Radiation , Gamma Rays , Liver Neoplasms/pathology , Neoplasms, Radiation-Induced/pathology , Time Factors
16.
Prikl Biokhim Mikrobiol ; 20(1): 79-87, 1984.
Article in Russian | MEDLINE | ID: mdl-6701163

ABSTRACT

A comparative study on immobilization of Citrobacter freundii cells by entrapment in carrageenan, agar, agar-agar, and gelatin gels (5, 10, and 15%) was carried out. Gelatin gels were treated with glutaraldehyde to make them more rigid. As a result, the tyrosine phenol-lyase activity of these samples was less than that of free cells (about 40%). The yield of TP-lyase activity was 40--60% when cells were immobilized in 5% and 7% agar and agar-agar gels. The cells entrapped in carrageenan gels, the concentration of which was varied from 2 to 10%, possessed the highest tyrosine phenol-lyase activity (up to 90%). The efficiency of cell entrapment was high for all the carrier and equal to 70--90%. The plastic strength and swelling of the above gels, as well as the phenol adsorption on the carriers and the release of the bacterial cells from them were studied under the conditions of tyrosine phenol-lyase reaction.


Subject(s)
Citrobacter/enzymology , Enzymes, Immobilized/metabolism , Lyases/metabolism , Tyrosine Phenol-Lyase/metabolism , Adsorption , Gels , Kinetics , Methods , Phenols/metabolism , Tyrosine/biosynthesis
18.
Kosm Biol Aviakosm Med ; 17(2): 73-6, 1983.
Article in Russian | MEDLINE | ID: mdl-6855178

ABSTRACT

This paper presents data on pulmonary circulation of rats during prolonged hypokinesia (30 to 165 days). It was found that the hypokinetic exposure of 30 to 60 days produced venous and, in particular, capillary plethora associated with blood redistribution and pooling in the lungs. As the exposure continued, the plethora level decreased due to the development of compensatory-adaptive reactions in the lung vessels. For instance, on hypokinetic day 90 small arteries of the muscle type developed a spasm which accelerated circulation stabilization. By hypokinetic days 120-165 pulmonary circulation returned to normal due to the further development of compensatory-adaptive mechanisms in lung vessels (tendency for hypertrophy of the media of small arteries and increase of its cross-sectional area).


Subject(s)
Pulmonary Circulation , Restraint, Physical/adverse effects , Animals , Capillaries/pathology , Hemodynamics , Lung/pathology , Male , Pulmonary Artery/pathology , Pulmonary Veins/pathology , Rats , Rats, Inbred Strains , Time Factors
20.
Prikl Biokhim Mikrobiol ; 18(5): 681-7, 1982.
Article in Russian | MEDLINE | ID: mdl-6755439

ABSTRACT

Experiments were carried out to investigate the process of a continuous enzymatic synthesis of L-aspartic acid from ammonium fumarate in uniform filling flow reactors. Escherichia coli (Soviet strain 85) cells immobilized in polyacrylamide gel granules reinforced by a solid carrier were used as biocatalysts. The conditions, under which a high aspartase activity of the biocatalyst and a stable hydrodynamic performance of the reactor were maintained, were determined. The main kinetic characteristics of a continuous performance of the reactor for 150 days were obtained.


Subject(s)
Aspartic Acid/chemical synthesis , Enzymes, Immobilized/metabolism , Escherichia coli/enzymology , Acrylic Resins , Aspartate Ammonia-Lyase/metabolism , Catalysis , Drug Stability , Fumarates/metabolism , Kinetics , Mathematics , Time Factors
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