[Change in the structural organization of Mycobacterium rubrum cells upon the action of ethidium bromide]. / Izmenenie strukturnoi organizatsii kletok Mycobacterium rubrum pri deistvii étidiuma bromida.

The action of ethidium bromide on Mycobacterium rubrum cells was studied. The culture growth was found to depend on ethidium bromide (EB) concentration in the medium. The reaction of EB with nucleoid DNA was shown to be specific and changes in the nucleoid structure were detected. Low EB doses (ca. 2 micrograms/ml) caused DNA despiralization in many cells. The process was reversible, which accounted for the elevated ability of reactivation at low EB doses. A higher EB dose (ca. 5-10 micrograms/ml and more) made the nucleoid structure coarser and denser in most cells and the nucleoid broke down to small fragments. As a result, due to the pool of enzymes present in the cells prior to EB addition, secondary changes developed. They involved all the cellular structures as well as the metabolism of lipids, polyphosphates, and glycogen. As a rule, these changes were incompatible with the cell viability.

[Structural and ultrastructural changes in Mycobacterium rubrum cells exposed to penicillin]. / Strukturnye i ul'trastrukturnye izmeneniia kletok Mycobacterium rubrum pri vozdeistvii na nikh penitsillinom.

The action of penicillin taken at subbacterioscopic doses on Mycobacterium rubrum cells causes changes in the size and shape of the cells, in the structure of the cell wall, in the intracellular membrane systems and in functions associated with them, and in the structure of nucleoids whose DNA packing becomes more loose. If the antibiotic is added at bacteriostatic doses, the size and shape of the cells do not change, but peptidoglycan precursors being synthesized are not incorporated into the polymer and accumulate in the periplasm. DNA overspiralization in nucleoids is a non-specific reaction, which indicates that DNA is physiologically passive. DNA is isolated with a membrane from the cytoplasm in certain cells. It is possible that the resistance of cells against penicillin is associated with the capability of DNA to become inactive in physiological terms.

[Study of the effect of the fungicide zineb on microorganisms]. / Izuchenie vliianiia fungitsida tsineba na mikroorganizmy.

Changes in yeast cells induced by the fungicide zineb were studied using biochemical, genetic techniques and electron microscopy. The primary changes involved anabolic processes since RNA and protein content increased in the cells. The data were consistent with a larger size of mitochondria. The oxidative-reductive activity of cell extracts did not change under the action of the fungicide. Zineb at a concentration of 0.5 to 50 mg/litre exerted a genetic activity towards indicator microorganisms. The changes in the morphophysiological characteristics of yeast growth under the action of zineb are presumed to be of a protective nature. Zineb traces in soil must be controlled in terms of the microbiological index.

[Characteristics of the ultrastructural organization of Actinomyces rimosus and Actinomyces violocinereus in monocultures and in an association producing extracellular proteases]. / Osobennosti ul'trastrukturnoi organizatsii Actinomyces rimosus i Actinomyces violocinereus v monokul'turakh i v assotsiatsii, produtsiruiushchei vnekletochnye proteazy.

The ultrastructural organization of Actinomyces rimosus and Actinomyces violocinereus was compared in monocultures and in associations. The cells of the two species can be discriminated by certain cytological characteristics. A rimosus predominated under the studied conditions and periods of growth. This organism had growth processes disordered (intrahyphal growth). A. violocinereus was characterized by the following processes in the association: peptidoglycan hypersynthesis, formation of calloses of the cell wall which occurred in parallel to hypertrophy of mesosomes, a loss of the capability to form capsules, and delayed spore formation. The reduced synthesis of granular and fibrillar material indicated that these products were not associated with exoprotease. The enzymatic activity was higher and could be detected in earlier in the association than in the monoculture of A. rimosus.

[Effect of sulfur-containing compounds on the ultrastructural organization of the cell wall of Candida utilis yeasts]. / Vliianie serosoderzhashchikh soedinenii na ul'trastrukturnuiu organizatsiiu kletochnoi stenki drozhzhei Candida utilis.

The effect of sulfur-containing compounds (cysteine, homocysteine, glutathione, cystine, and methionine) on the ultrastructural organization of the cell wall was studied in Candida utilis 295t by electron microscopy with the aid of staining SH groups by HgCl2. Treatment of the cells with cysteine and homocysteine was found to modify the ultrastructure of the cell wall: the capsule was damaged and the porosity increased, which facilitated the penetration of these compounds into the periplasm. Their further conversion in the cell has been studied.

[Carboxysomes of the thermophilic hydrogen bacterium Pseudomonas thermophila]. / Karboksisomy termofil'noi vodorodnoi bakterii Pseudomonas thermophila.

The technique of electron microscopy was used to detect the presence of paracrystal hexagonal inclusions in the cells and spheroplasts of the thermophilic hydrogen bacterium Pseudomonas thermophila. The connection of the inclusions with DNA threads can easily be seen on photomicrographs of the spheroplasts. The cells were disintegrated by freezing and thawing and the resultant homogenates were centrifuged in a sucrose density gradient; up to 80% of the activity of ribulose-1,5-diphosphate carboxylase (RDP carboxylase, EC 4.1.1.39) was found in the fraction of particles containing hexagonal paracrystal inclusions (carboxysomes). Their granular content and the tendency to diffuse were seen at a magnification x100,000. The percentage of the insoluble enzyme was higher in cells in the stationary growth phase than in growing cells. Only 25% of the enzyme activity was detected in the particles after the cells treated with lysozyme had been subjected to osmotic shock. A possible role of carboxysomes in cells as a compartment storing RDP carboxylase is discussed.

[Ultrastructural organizational characteristics of the hydrogen thermophilic bacterium, Pseudomonas thermophila]. / Osobennosti ul'trastrukturnoi organizatsii vodorodnoi termofil'noi bakterii Pseudomonas thermophila.

The ultrastructural organization of the lithotrophic hydrogen bacterium Pseudomonas thermophila K2 was described for the first time and was found to be typical of Gram-negative bacteria. The ultrastructure of this organism is characterized by (i) irregular plication of the outer membrane of the cell wall and a very thin (2-3 nm) rigid layer; (ii) a considerable number of intracellular membranes differing in their structure and location; (iii) fragmentation of the cytoplasm involving the plasmalemma and the cell wall; (iv) the presence, in the nucleoid zone, of paracrystals having a hexagonal shape and resembling carboxysomes in their size, shape and macromolecular organization, which had not been found in hydrogen bacteria hitherto.

[Relationship between the number of nucleoidosomes and the stage of development of Mycobacterium rubrum cultures]. / Izmenenie kolichestva nukleoidosom v zavisimosti ot stadii razvitiia kul'tury Mycobacterium rubrum.

This work has confirmed that the nucleoidosome (mesosome) of Gram-positive bacteria is a specialized invagination of the cytoplasmic membrane and serves for accommodating the replicative centres of nucleoid homologous chromosomes. The structure is not constant, it arises under specified conditions of cultivation and at certain growth stages which are characterized by decelerated division of nucleoids and cells while the rate of DNA replication does not change.

[Biological significance of nucleosomes in bacteria]. / O biologicheskom znakleoidosom u bakterii.

The paper presents data concerning the structural organization of specialized membrane structures in bacterial cells, viz. nucleoidosomes involved in DNA replication. A possible correlation between the number of homologous chromosomes in a nucleoid, the presence of nucleodosomes and their dimensions is discussed. Apparently, the role of nucleoidosomes is to increase the active surface of a plasmalemma region necessary to locate the replicative centers of circular DNA molecules in bacterial nucleoids.

[Ultrastructural organization of marine luminescent bacteria and their mutants]. / Osobennosti ul'trastrukturnoi organizatsii morskikh svetiashchikhsia bakterii i ikh mutantov.

The aim of this work was to study the submicroscopic organization of luminescent bacteria belonging to the genera Photobacterium and Lucibacterium as well as that of their "dark" mutants incapable of luminescence. The ultrastructural organization of all studied bacteria is typical of gram-negative species. The luminescent bacteria are characterized by the presence, in their cytoplasm, of osmophilic formations 22--110 nm in size. The cells of "dark" mutants accumulate volutin and contain complex membrane systems which are related to decelerated growth of the cultures.

[Structure and physico-chemical properties of bacterial flagella]. / Struktura i fiziko-khimicheskie svoistva bakterial'nykh zhgutikov.

The structural organization of bacterial flagella was studied with Bacillus brevis and Escherichia coli MS 1350. The presence of a spherical body at the basis of a flagellum was confirmed. The structural organization of ingredients of the flagellar appratus, its inner and outer part, was investigated. The molecular weight of protein subunits in the filamentous portion of the flagellum was assayed as well as their amino acid composition. The mode of attachment of the flagellum to the cell is discussed.

[Structural changes in Mycobacterium rubrum cells under the influence of chloroethylamine]. / Izmenenie struktury kletok Mycobacterium rubrum pod vliianiem khlorétilamina.

Chloroethylamine was used to differentiate the membranous structures of bacterial cells whose physiological role becomes more pronounced under the action of this substance. The following changes were found: in the synthesis of the cell wall as a result of modifications in the structure of mesosomes which control the correct orientation of growth and cell division; in the nucleoid and nucleoidosomes; in the analogues of mitochondria characterizing the level of energy metabolism and in the analogues of the endoplasmic reticulum accompanied with changes in the synthesis of metabolites and reserve substances in the cells. Changes in the structure and ultrastructure of the bacteria under the action of irradiation and the radiomimetic substance chloroethylamine are analyzed.

[Effect of ionizing radiation on the structural and ultrastructural organization of Mycobacterium rubrum]. / Deistvie ioniziruiushchego izlucheniia na strukturnuiu i ul'trastrukturnuiu organizatsiiu Mycobacterium rubrum.

The structural and ultrastructural organization of Mycobacterium rubrum cells was studied in the course of normal growth and in the conditions of irradiation. The cytomorphological differentiation of the bacterial membrane structure was shown as well as their functional role. Ionizing radiation was used as a tool for revealing the role of the membrane structures; the latter were found to be related to a certain cellular function. Damages of various, individually functioning membrane systems upon the action of ionizing radiation on the cell are described. Mesosomes are absent from the cells if the synthesis of peptidoglycan is inhibited, whereas hypersynthesis of the cell wall material is observed upon their hypertrophy. The content of mitochondrial analogs in the cell increases with the rate of metabolic processes. The function of cellular division is disturbed as a result of damages in the nucleoid DNA structure and degradation of nucleoidosomes. Changes in carbohydrate and lipid metabolism are also observed.

[Change in the structural organization of the respiratory apparatus of Mycobacterium rubrum depending on the cultivation conditions]. / Izmenenie strukturnoi organizatsii dykhatel'nogo apparata Mycobacterium rubrum v zavisimosti ot uslovii kul'tivirovaniia.

Changes in the respiration apparatus of Mycobacterium rubrum were studied in the lag phase. The number of mitochondrial analogues was found to increase in parallel with the cellular growth, reaching a certain density of distribution per unit surface of the cells. The analogues of mitochondria were very labile. They rearranged easily, depending on the conditions of bacterial cultivation, but were always present in the cells as a discrete structure. The cellular growth and an increase of the mitochondrial analogues in them at 24 and 37 degrees C ceased by the 6-8th hr, regardless of the presence of glucose in the medium. Transition of the culture to the log phase at 24 degrees C was delayed to 16-18 hrs. After division, cells cultivated in media containing glucose were much larger than those grown in media without glucose, and the density of distribution in them of the mitochondrial analogues was higher. A decrease of temperature had no effect on the bacterial growth, but inhibited their division. The rate of oxygen uptake by cell suspensions at different periods of the lag phase correlated with the content of the mitochondrial analogues in them.

[Effect of acute cardiac ischemia on the activity of the protein synthesizing system of the internal membranes of myocardial mitochondria]. / Deistvie ostroi ishemii serdtsa na aktivnost' beloksinteziruiushchei sistemy vnutrennikh membran mitokhondrii miokarda.

The effect of acute experimental heart ischemia on protein synthesis and RNA of the internal membranes of myocardial mitochondria was studied; there was a sharp increase in the protein synthesizing system activity of the internal mitochondrial membranes. The most pronounced protein and PNA exchange was noted on the 7th day of the infarction; apparently it was the most critical time in the development of the given pathological process. A study of ultrastructure of mitochondrial membranes in the course of experimental infarction development demonstrated marked changes in their ultrastructure depending on the severity of the disease.

[Cryofractographic study of the structure of yeast cells found in an anabiotic state]. / Kriofraktograficheskoe issledovanie struktury drozhzhevykh kletok, nakhodiashchikhsia v anabioticheskom sostoianii.

Cryofractographic studies of normally growing yeast cells have shown that the length, number and arrangement of slit-like invaginations, as well as the number, frequency of arrangement and dimensions of pores on the nucleolemma, differ among various yeast species. The data on the structure of various organoids published earlier have been confirmed. The volume of all cellular organoids, with an exception of mitochondria, decreases upon dehydration. The invaginations of the plasmalemma coalesce to form a common network. This is important in the course of changes in the volume and density of the cytoplasm of cells in the anabiotic state, maintaining the structural connection of the plasmalemma with the cellular contents, which is necessary for the survival of an organism under extreme conditions.

[Polysaccharides of free slime, capsule and cell wall of Mycobacterium lacticolum]. / Polisakharidy svobodnoi slizi, kapsuly i kletochnoi stenki Mycobacterium lacticolum

Free and capsule exopolysaccharides of Mycobacterium lacticolum 121 contain glucose, glucuronic acid, and unidentified monomer. Arabinogalactan typical of mycobacteria was found in the cell walls of this culture. The exocellular polysaccharide of Mycobacterium lacticolum 121 is not the product of synthesis of the cell wall.

[Intracellular membrane structures of Bdellovibrio bacteriovorus during development in the bacterial host cell]. / Vnutrikletochnye membrannye struktury Bdellovibrio bacteriovorus pri razvitii v kletke baktteri-khoziaina

Electron microscope investigation of intracellular membrane structures of Bd. bacteriovorous during its intracellular growth and development has been carried out. Increased amount of membrane structures has been stated. Along with simply organized invaginations of plasmalemma, complicated membrane structures resembling mesosomes of grampositive bacteria are observed. Localization of these structures testifies to their involvement in the synthesis of exotoxins and exoenzymes.

[Localization of cellulase in the Aspergillus terreus mycelial cells]. / Lokalizatsiia tselliulazy v kletkakh mitseliia Aspergillus terreus

Localization of cellulase was studied in the cells of Aspergillus terreus 17P, a thermotolerant fungus. The activity of Cx-enzyme was found in the supernatant and to be of a protein nature, as was established by means of differential centrifugation of a homogenate of the mycelium cells. Ultrathin sections of the mycelium were fixed according to Somogi and studied by electron microscopy. The cellulase was found to be located on the surface of the cell wall to which it was bound but not very firmly, and was therefore detected in the supernatant.