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  • 11
    ISSN: 1432-072X
    Keywords: Continuous Culture ; Rhodopseudomonas capsulata ; Bacteriochlorophyll ; Protein ; Poly-β-Hydroxybutyrate ; Nitrogen Limitation ; Oxygen Control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A continuous culture apparatus is described, which allows cultivation of photosynthetic bacteria anaerobically in the light and semiaerobically in the dark at constant oxygen tensions. The growth-parameters 1. substrate concentration at half maximum growth rate (K s) and 2. yield (Y) forRhodopseudomonas capsulata are calculated. An automatic control system of the oxygen partial pressure in the culture medium is elaborated. It is shown, that the discontinuous regulation with a control unit in connection with two magnetic valves, which give short pulses of either oxygen-free gas or gas mixed with oxygen, is an economic, practicable and reliable method. The yield coefficientY during growth limited by ammonium sulfate is variable due to the synthesis of nitrogen independent metabolites, such as poly-β-hydroxybutyrate. The storage of poly-β-hydroxybutyrate in continuous culture is a function of both the actual concentration of ammonia and of theC/N ratio. At very low growth rates (1/6 µ m ) the poly-β-hydroxybutyrate content increases amounting to 33% of the dry weight. In semiaerobically dark grown cells (pO2: 5 mm Hg) the protein and bacteriochlorophyll content increased definitely on dry weight basis with increasing growth rates. In contrast, in anaerobic light cultures only a small increase of the bacteriochlorophyll level but no change of the protein content per dry weight of cells was observed at increasing growth rates.
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  • 12
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The isolation and chemical characterization of the lipopolysaccharides (O-antigens) of 12 strains of the gram-negative photosynthetic bacterium Rhodopseudomonas palustris is described. Lipopolysaccharides (LPS) were extractable with phenol/water, however, the bulk of the LPS of all strains remained in the phenol phase and only trace amounts were found in the aqueous layer. The LPS was also extractable by a phenol/chloroform/petroleum ether mixture (PCP-method), recommended for lipophilic glycolipids. Neither incubation of living bacteria with EDTA nor with NaCl liberated appreciable amounts of LPS-protein-lipid conjugates from the cells. 2. All strains investigated were found to have galactose, mannose, heptose, 2-keto-3-deoxyoctonate (KDO), glucosamine, 6-deoxy-glucosamine (quinovosamine) and a recently identified sugar, a 2,3-diamino-2,3-dideoxyhexose, as common LPS constituents. The presence of additional sugars allowed the classification of the strains into three distinct chemotypes. Chemotype I contains 4-O-methyl-D-xylose, and several non-identified amphoteric amino sugars. Chemotype II contains 4-O-methyl-D-xylose, 3-O-methyl-6-deoxy-D-talose, 6-deoxy-talose, xylose and again some unidentified amphoteric amino sugars, which were different from those of chemotype I. In chemotype III xylose, glucose, rhamnose, galactosamine and 6-O-methyl-glucosamine were identified. The main fatty acid in the high molecular weight material from the phenol phase of phenol/water extracts of all strains is β-hydroxymyristic acid. In addition in all strains β-hydroxypalmitic, palmitic and stearic acids were found. It has still to be proven that all these fatty acids are LPS constituents. 3. Like enteric LPS the LPS of R. palustris can be split by mild acid hydrolysis in a lipid portion (lipid A) and the degraded polysaccharide. But contrary to enteric lipid A, the lipid A of R. palustris does not contain glucosamine, but has the 2,3-diamino-hexose as the only amino sugar constituent. The possible occurrence of a common R-core and the question if repeating units exist in the O-specific chains of R. palustris LPS are discussed. 4. In two strains small amounts of additional LPS, which differ in their chemical composition from the respective LPS of the phenol phase, were isolated from the aqueous phase.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 96 (1974), S. 161-174 
    ISSN: 1432-072X
    Keywords: Membrane Proteins ; Reaction Center ; Intracytoplasmic Membrane ; Rhodopseudomonas capsulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Intracytoplasmic membranes of wild type strain 37 b 4 and mutant strains A1a car-bchl-, A1a car-bchl+ ofRhodopseudomonas capsulata were isolated. The membrane proteins were solubilized and separated by polyacrylamide gel electrophoresis (methods of Takayamaet al., 1964; Weber and Osborn, 1969). The band patterns were compared with each other. From the strain A1a car-bchl+ reaction center particles were isolated by treatment of membrane with Triton X-100 followed by sucrose density gradient centrifugation. The reaction center particles were found to be enriched in reaction center bacteriochlorophyll. This pigment shows a reversible bleaching at 855 nm and a blue shift at 798 nm. The light harvesting bacteriochlorophyll portion of this fraction was 14–22% of the total bacteriochlorophyll content. The three main proteins of the reaction center particles amount to about 80% of the total protein of the particles. The molecular weights of the main proteins were estimated to be 32000, 27500 and 22500 daltons.
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  • 14
    ISSN: 1432-072X
    Keywords: Rhodopseudomonas palustris ; O-Antigens ; Serology ; Lipopolysaccharides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die isolierten O-Antigen (Lipopolysaccharide) aus 12 Rhodopseudomonas palustris-Stämmen konnten drei verschiedenen Serotypen zugeordnet werden. Diese decken sich mit der kürzlich erarbeiteten Chemotypisierung dieser O-Antigene. Im passiven Hämagglutinationstest, der mit den Lipopolysacchariden der Stämme 2/2, K/1 (Chemotyp I), sowie 8/1, 1e5 (Chemotyp II) und 11/1, 15, 1a1, 42 (Chemotyp III) und den entsprechenden Antiseren gegen diese Stämme ausgeführt wurde, zeigten die O-Antigene nur innerhalb eines Chemotyps Kreuzreaktionen. Zwischen Lipopolysacchariden verschiedener Chemotypen wurden in keinem Fall Kreuzreaktionen beobachtet. Entsprechende Ergebnisse wurden durch Immunelektrophorese und im Agargel-Präcipitationstest nach Ouchterlony erhalten, bei welchen die Lipopolysaccharide der Stämme 8/1 (Chemotyp II) und 11/1 (Chemotyp III) mit den homologen und den gegen die übrigen Stämme gerichteten heterologen Antiseren getestet wurden. Durch Kreuzabsorptionen der Antiseren wurde für die dem Chemotyp III zugehörenden Stämme 11/1, 15 und 1a1 O-Identität nachgewiesen. Die weitgehende Parallelität von Chemo- und Serotyp hat somit nicht nur für Enterobacteriaceae, sondern auch für die taxonomisch weit entfernten Rhodospirillaceae Gültigkeit. Jedoch sind die Serotypen bzw. Chemotypen der untersuchten Stämme nicht als selbständige Taxa anzusehen. Mit Lipopolysacchariden aus anderen Rhodospirillaceae-Species (Rhodopseudomonas capsulata, Rhodopseudomonas viridis, Rhodopseudomonas gelatinosa, Rhodospirillum rubrum) wurde in keinem Fall Kreuzreaktion erhalten.
    Notes: Abstract Serological investigations carried out with isolated O-antigens (lipopolysaccharides) of 12 strains of Rhodopseudomonas palustris showed that these O-antigens can be arranged into 3 distinct serotypes. These are identical with the three chemotypes previously established. The passive hemagglutination test carried out with isolated lipopolysaccharides of the strains 2/2 and K/1 of chemotype I, strains 8/1 and 1 e5 of chemotype II and strains 11/1, 15, 1a1 and 42 of chemotype III and their respective rabbit antisera showed that crossreactions can only be observed in between the chemotypes. No cross-reactions were observed between O-antigens of different chemotypes. This result was essentially confirmed by gel-precipitation studies (according to Ouchterlony) and in immunoelectrophoresis using the alkali-treated lipopolysaccharides of strains 8/1 (chemotype II) and 11/1 (chemotype III) as test antigens and antisera against strains of chemotypes I–III. Cross absorptions carried out with strains 11/1, 15 and 1a1, all belonging to chemotype III, showed identity of their O-antigens. The earlier established rather far-reaching parallelity of chemo- and serotypes existing in Enterobacteriaceae is therefore also valid for the taxonomically remote Rhodospirillaceae. In contrast to Enterobacteriaceae the different serotypes of Rhodopseudomonas palustris are not distinct taxa. Additional studies carried out with isolated lipopolysaccharides of other species of Rhodospirillaceae (Rhodopseudomonas capsulata, viridis and gelatinosa and Rhodospirillum rubrum) failed to show any cross reactivities with the three serotypes of Rhodopseudomonas palustris.
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  • 15
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two carotenoid less mutant strains of Rhodopseudomonas capsulata were isolated. The strain A1a pho- was not able to grow photosynthetically and to synthesize bacteriochlorophyll. However, this organism produced protochlorophyll (phytol ester of Mg-2-vinylpheoporphyrin a5 monomethylester) and protopheophytin. Both pigments were excreted as a macromolecular complex. The intracellular membrane system was poorly developed. A revertant strain of A1a (pho+) was isolated which was able to grow anaerobically in the light as well as aerobically in the dark. The generation time under photosynthetic conditions amounted to 16 hrs whereas under aerobic conditions in the dark that was found to be 2.8 hrs. In addition to bacteriochlorophyll, which was found exclusively in the membrane fraction, protochlorophyll and protopheophytin were synthesized and excreted. A small amount of these pigments was also found intracellulary in the membrane fraction. The structure of the well developed intracytoplasmic membrane reticulum was described.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 23 (1955), S. 1-13 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 128 (1981), S. 376-383 
    ISSN: 1432-072X
    Keywords: Bacteriochlorophyll a ; Associated polypeptides ; Rhodopseudomonas capsulata ; Membrane differentiation ; Photosynthetic apparatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Early stages in the formation of membranes and photosynthetic units were studied under growth-limiting phototrophic and chemotrophic conditions in cells of Rhodopseudomonas capsulata. The incorporation of polypeptides, forming bacteriochlorophyll-carotinoid-protein complexes in the membrane, was followed by use of pulse-labeling and immunoprecipitation techniques. The newly synthesized polypeptides were inserted into two distinct membrane fractions at both different rates and proportions. The two membrane fractions differed in sedimentation behavior, absorption spectra and activities of the respiratory chain. The individual pigment-associated proteins did not exhibit precursor-product relationship between the two membrane fractions. The data suggest that newly synthesized polypeptides were integrated both into cytoplasmic and pre-existing intracytoplasmic membranes, where the proteins and pigments were assembled to form reaction centers and light-harvesting pigment-protein complexes.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 128 (1981), S. 390-393 
    ISSN: 1432-072X
    Keywords: Conjugational transfer ; R plasmids ; Rhodopseudomonas capsulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plasmids RP1, R68.45 and RP4::Mu cts 61 were transferred into Rhodopseudomonas capsulata from Escherichia coli. The frequency of intraspecies transfer of these plasmids in R. capsulata was 10-4–10-5 per donor. The plasmids also mobilized chromosomal genes at a low frequency. Phototrophic recombinants from matings between recipient strains defective in the photosynthetic-apparatus and wild type donors were obtained at a frequency of 10-7–10-8 per donor.
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  • 19
    ISSN: 1432-072X
    Keywords: Absorption spectra ; Fluorescence emission spectra ; Carotenoid band shift ; Excition transfer ; Light-harvesting complexes ; Rhodopseudomonas capsulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Intracytoplasmic membranes of the mutant strain NK3 of Rhodopseudomonas capsulata lacking the lightharvesting complex B800-850 were fused with proteoliposomes containing the B800-850 complex. Fluorescence emission spectroscopy at 77K showed that after fusion the fluorescence of the B850 bacteriochlorophyll disappeared nearly completely and the B870 fluorescence became prominent. This result and control experiments with proteoliposome-chromatophore mixture and with chromatophore and solubilized B800-850 complexes, respectively, indicate that in fused membranes a reorientation of membrane particles took place and excitons migrated from B850 to B870 bacteriochlorophyll. In fused proteoliposome-chromatophore vesicles a light-induced carotenoid band shift was observed, reflecting the building of an electrical membrane potential due to chargeseparation. Carotenoid band shift was not observed in separated proteoliposomes and NK3 chromatophores. It is concluded that by membrane fusion and lateral diffusion of membrane particles reaction center-light-harvesting B870 complexes came in functional contact with B800-850 antenna complexes.
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  • 20
    ISSN: 1432-072X
    Keywords: Membrane Differentiation ; Reaction Center ; Bacteriochlorophyll ; Antenna-Pigment Complex ; Bacteriochlorophyll-Protein Association ; Photosynthetic Bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Formation of the photosynthetic apparatus was induced in aerobically grown dark cultures of Rhodopseudomonas capsulata by lowering of the oxygen tension. Besides the wild type strain the carotenoid-less mutant strain A1a+ was investigated. Both strains exhibited initially a decrease of the molar ratio of total bacteriochlorophyll (Bchl) to reaction center (RC) Bchl, followed by an increase. Synthesis of RC-Bchl preceded the synthesis of light-harvesting (LH) Bchl. Activities of photophosphorylation in membrane preparations, isolated from cultures after different periods of incubation at low aeration, decreased on the basis of total Bchl from about 9 to 2 μmole ATP/μmole total Bchl·min, whereas the rate on the basis of RC-Bchl remained constant (about 500 μmole ATP/μmole RC-Bchl·min). Under the same conditions the membrane proteins were labelled with U−14C-protein hydrolysate. Corresponding to RC-Bchl the synthesis of RC-proteins dominated during the first 30 min of incubation at pO2 below 3 mmHg. After 45–60 min of membrane formation at low aeration the synthesis of LH-complex proteins exceeded the synthesis of RC proteins. The correlations between protein and Bchl synthesis in the sequential formation of RC- and LH-complexes are discussed.
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