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  • 1
    ISSN: 1432-072X
    Keywords: R-Bodies ; Kappa particles ; Free-living hydrogen bacteria ; Induction ; Electron microscopy ; Chemical composition ; Defective prophages ; Plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract R-Bodies have been found in a recently isolated pseudomonas-like free-living hydrogen oxidizing bacterium. Their isolation, fine structure and chemical composition are described and compared with the R-bodies from the kappa particles (Caedobacter), obligate endosymbionts of Paramecium aurelia. The 2K 1 R-bodies exhibited essential characteristics of the kappa R-bodies; however, their size and some other structural aspects proved that they represent a new type of R-bodies. The presence of phage tail-like particles in cells induced with Mitomycin C is in favour of the hypothesis that the R-bodies might be coded by defective prophages, or by extrachromosomal elements.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Micromorphology ; Gram-negative hydrogen bacteria ; Flagellation ; Flagellar fine structure ; Pili
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cell morphology, the arrangement and fine structure of flagella and the piliation of the following Gram-negative aerobic hydrogen bacteria have been studied: Alcaligenes eutrophus, Alcaligenes paradoxus, Alcaligenes ruhlandii, Pseudomonas flava, Pseudomonas pseudoflava, Pseudomonas palleronii, Pseudomonas facilis, Aquaspirillum autotrophicum, Paracoccus denitrificans, Corynebacterium autotrophicum, and strains MA 2 and SA 35. The identity of the bacteria was examined by their substrate spectra and type of flagellation. Three types of flagellar fine structure were differentiated. The presence of pili was noted in strains of Alcaligenes paradoxus, Pseudomonas flava, P. pseudoflava, P. palleronii, and P. facilis.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Micromorphology ; Gram-negative ; Hydrogen bacteria ; Cell envelope ; Cytoplasmic inclusions ; Membranes ; Mesosomes ; Glycogen ; Poly-β-hydroxybutyrate ; Cell wall types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fine structure of the cell envelope, of membrane systems and of cytoplasmic inclusions of Gram-negative aerobic hydrogen bacteria has been studied. The results have been tabulated, and three main groups could be recognized: Group 1: Alcaligenes eutrophus, A. paradoxus, A. ruhlandii, Pseudomonas facilis, P. flava, P. pseudoflava, P. palleronii, and Aquaspirillum autotrophicum; Group 2: “Corynebacterium” autotrophicum and strains MA 2 and SA 35; Group 3: Paracoccus denitrificans. Special structures related to the chemoautotrophic way of life of the hydrogen bacteria were not observed.
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  • 4
    ISSN: 1432-072X
    Keywords: Aquaspirillum autotrophicum ; Hydrogen bacterium ; Growth ; Chemolithoautotrophy ; Particulate hydrogenase ; Induction ; Repression ; Natural habitats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aquaspirillum autrotrophicum, an aerobic hydrogen bacterium recently isolated from an eutrophic freshwater lake, was characterized physiologically. It grew autotrophically in a fermenter with a doubling time of 4 h. Heterotrophic growth was faster. pH-Optimum ranged from 5.0–7.5, temperature optimum was about 28° C. During autotrophic growth about 10 moles hydrogen were consumed per 1 mole carbon dioxide fixed. Hydrogenase activity is inducible. CO2 did not enhance the oxy-hydrogen reaction by intact cells. The hydrogenase activity was localized in the particulate fraction. The hydrogenase reduced methylene blue and phenazine methosulfate; pyridine nucleotides were not reduced. In cell-free extracts, hydrogenase was sensitive to oxygen. Ribulosebisphosphate carboxylase was present in autotrophically-grown cells and absent from heterotrophically grown cells. Hydrogenase induction in heterotrophically-grown cells followed parabolic kinetics. Oxygen and D-gluconate repressed hydrogenase synthesis, whereas citrate, DL-lactate and pyruvate stimulated its formation. The repressive effect was delayed. The results suggest that the control of hydrogenase synthesis occurred at the transcriptional level, and that mRNA coding for the hydrogenase had a relatively long life span. D-Gluconate was degraded via the Entner-Doudoroff pathway, the enzymes of which were constitutively formed. Enzymes of the pentosephosphate and Embden-Meyerhof pathways (except phosphofructokinase) were present, too. Hydrogen did not inhibit heterotrophic growth. The possible competitive advantage of the physiological properties described with regard to the natural habitat was discussed.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 22 (1980), S. 1895-1906 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Empirical estimations of H2O2 concentration in a system containing bovine liver catalase and continually supplied with H2O2 were done to evaluate the efficiency of the enzyme to cleave H2O2. It was found that the continuous addition of H2O2 leads to the formation of steady-state concentrations of H2O2 in the medium. At a constant catalase concentration both the level and the duration of the steady state are dependent on the flow rate of H2O2. The increase of the catalase concentration in the medium does not change the steady-state level, it merely leads to the maintenance of the steady state for longer durations. At higher flow rates of H2O2, no steady state could be maintained, even when catalase was present in high excess. The incomplete cleavage of H2O2 by catalase under these conditions is due to the low affinity of catalase toward H2O2 (high Km value, apparent Km = 0.1M H2O2) and to the rapid inactivation of the enzyme during the continuous addition of H2O2.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 22 (1980), S. 1877-1894 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The supply of heterotrophically growing suspensions of Alcaligenes eutrophus PHB-4 with oxygen formed by the continuous addition of H2O2 in the presence of bovine liver catalase was found to be restricted to well-defined conditions. The catalase-H2O2 system proved to be suitable during the growth at low cell densities equivalent to 2 g dry weight/liter. When under these conditions the oxygen concentration was held constant at 1.8 mg O2/liter, the cells grew for 6-8 hr at a rate almost identical to that observed with conventional aeration. However, aeration with H2O2 for longer durations (10-20 hr) and at higher cell densities (5-20 g dry weight/liter) led invariably to cell damage and retardation of growth. The impairment of growth observed during the oxygen supply by the catalase-H2O2 system was traced back to the formation of gradually increasing steady-state concentrations of H2O2 in the medium. Possible sites of cell damage by H2O2 such as membrane function, excretion and function of siderophores, and synthesis of cell polymers have been studied, and the cytotoxic mechanism of low concentrations of H2O2 was discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A catalase has been purified from aerobically grown Escherichia coli K12. The enzyme exhibits unorthodox properties compared with catalyse from bovine liver and seems to be identical to hydroperoxidase II from E. coli. A mathematical model is presented which makes it possible to calculate the steady-state concentration of hydrogen peroxide in an open system. The model has been verified experimentally. It has been shown that the catalase from E. coli is better suited than the bovine liver enzyme for oxygen supply to cell suspensions using hydrogen peroxide.
    Additional Material: 1 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 19 (1977), S. 413-424 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Oxygen has been supplied to suspensions of microorganisms kept under nitrogen by the addition of hydrogen peroxide. If catalase was present in the suspension and the flow was adjusted to the rate of oxygen consumption, the cells grew at rates identical to the controls incubated under air. The applicability of oxygen supply by hydrogen peroxide and its limits are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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