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  • 1
    Electronic Resource
    Electronic Resource
    Direct isolation of functional genes encoding cellulases from the microbial consortia in a thermophilic, anaerobic digester maintained on lignocellulose (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 667-674 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Gene libraries (“zoolibraries”) were constructed in Escherichia coli using DNA isolated from the mixed liquor of thermophilic, anaerobic digesters, which were in continuous operation with lignocellulosic feedstocks for over 10 years. Clones expressing cellulase and xylosidase were readily recovered from these libraries. Four clones that hydrolyzed carboxymethylcellulose and methylumbelliferyl-β-d-cellobiopyranoside were characterized. All four cellulases exhibited temperature optima (60–65° C) and pH optima (pH 6–7) in accordance with conditions of the enrichment. The DNA sequence of the insert in one clone (plasmid pFGH1) was determined. This plasmid encoded an endoglucanase (celA) and part of a putative β-glucosidase (celB), both of which were distinctly different from all previously reported homologues. CelA protein shared limited homology with members of the A3 subfamily of cellulases, being similar to endoglucanase C from Clostridium thermocellum (40% identity). The N-terminal part of CelB protein was most similar to β-glucosidase from Pseudomonas fluorescens subsp. cellulosa (28% homology). The use of zoolibraries constructed from natural or laboratory enrichment cultures offers the potential to discover many new enzymes for biotechnological applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00164771
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Direct isolation of functional genes encoding cellulases from the microbial consortia in a thermophilic, anaerobic digester maintained on lignocellulose (1995)
    Springer
    Applied microbiology and biotechnology 43 (1995), S. 667-674 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Gene libraries (“zoolibraries”) were constructed in Escherichia coli using DNA isolated from the mixed liquor of thermophilic, anaerobic digesters, which were in continuous operation with lignocellulosic feedstocks for over 10 years. Clones expressing cellulase and xylosidase were readily recovered from these libraries. Four clones that hydrolyzed carboxymethylcellulose and methylumbelliferyl-β-D-cellobiopyranoside were characterized. All four cellulases exhibited temperature optima (60–65 °C) and pH optima (pH 6–7) in accordance with conditions of the enrichment. The DNA sequence of the insert in one clone (plasmid pFGH1) was determined. This plasmid encoded an endoglucanase (celA) and part of a putative β-glucosidase (celB), both of which were distinctly different from all previously reported homologues. CelA protein shared limited homology with members of the A3 subfamily of cellulases, being similar to endoglucanase C from Clostridium thermocellum (40% identity). The N-terminal part of CelB protein was most similar to β-glucosidase from Pseudomonas fluorescens subsp. cellulosa (28% homology). The use of zoolibraries constructed from natural or laboratory enrichment cultures offers the potential to discover many new enzymes for biotechnological applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00164771
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Immunocytochemical localization of methyl-coenzyme M reductase in Methanobacterium thermoautotrophicum (1987)
    Springer
    Archives of microbiology 147 (1987), S. 190-194 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium thermoautotrophicum ; Methyl-CoM reductase ; Immunocytochemistry ; Colloidal gold ; Energy conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cells of Methanobacterium thermoautotrophicum were fixed with glutaraldehyde, sectioned and labeled with antibodies against the β subunit of component C (=methyl-CoM reductase) of methyl-CoM reductase system and with colloidal gold-labeled protein A. It was found that the gold particles were located predominantly in the vicinity of the cytoplasmic membrane, when the cells were grown under conditions where methyl-CoM reductase was not overproduced. This finding confirms the recent data obtained with Methanococcus voltae showing via the same immunocytochemical localization technique that in this organism methyl-CoM reductase is membrane associated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00415283
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  • 4
    Electronic Resource
    Electronic Resource
    Elemental analysis of particles in fungal zoospores (1984)
    Springer
    Archives of microbiology 139 (1984), S. 102-104 
    Details
    ISSN: 1432-072X
    Keywords: Fungus ; Zoospore ; Blastocladiella ; Allomyces ; Gamma ; Particle ; Phosphate ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The elemental composition of gamma particles in zoospores ofAllomyces macrogynus andBlastocladiella emersonii was determined by use of energy dispersive X-ray analysis of glutaraldehyde fixed, thin section zoospores. Isolated preparations of gamma particles were also examined. Gamma particles contained no detectable elements. Similar sized, globular, electron dense cytoplasmic inclusions contained phosphorus and calcium. We suggest that previous studies assigning calcium and phosphorus to gamma particles may have been based on confusion of these two types of cytoplasmic inclusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692722
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  • 5
    Electronic Resource
    Electronic Resource
    Immunogold localization of coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase in Methanobacterium formicicum (1989)
    Springer
    Archives of microbiology 151 (1989), S. 307-313 
    Details
    ISSN: 1432-072X
    Keywords: Methanobacterium formicicum ; Formate dehydrogenase ; F420-hydrogenase ; Immunogold ; Ultrastructure ; Methanogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructural locations of the coenzyme F420-reducing formate dehydrogenase and coenzyme F420-reducing hydrogenase of Methanobacterium formicicum were determined using immunogold labeling of thin-sectioned, Lowicryl-embedded cells. Both enzymes were located predominantly at the cell membrane. Whole cells displayed minimal F420-dependent formate dehydrogenase activity or F420-dependent hydrogenase activity, and little activity was released upon osmotic shock treatment, suggesting that these enzymes are not soluble periplasmic proteins. Analysis of the deduced amino acid sequences of the formate dehydrogenase subunits revealed no hydrophobic regions that could qualify as putative membrane-spanning domains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406556
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  • 6
    Electronic Resource
    Electronic Resource
    Isolation and characterization of a carbon monoxide utilizing strain of the acetogen Peptostreptococcus productus (1987)
    Springer
    Archives of microbiology 148 (1987), S. 305-313 
    Details
    ISSN: 1432-072X
    Keywords: Acetogenic bacteria ; Peptostreptococcus productus ; Carbon monoxide utilization ; Cell wall structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract From sludge obtained from the sewage digester plant in Marburg-Cappel a strictly anaerobic bacterium was enriched and isolated with carbon monoxide as the sole energy source. Based on morphological and physiological characteristics the isolate was identified as a strain of Peptostreptococcus productus, which was called strain Marburg. The organism was able to grow on CO (50% at 200 kPa) as the sole energy source at a doubling time of 3 h and converted this substrate to acetate and CO2. The type strain of P. productus was not able to grow at the expense of CO. Electron microscopic investigations of strain Marburg cells revealed a cell wall which was different from that of other Gram-positive prokaryotes. DNA:DNA hybridization studies of the DNA isolated from strain Marburg and the type strain as well as some morphological and physiological properties of both strains confirmed the low degree or relatedness between the two strains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00456709
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  • 7
    Electronic Resource
    Electronic Resource
    A histochemical and ultrastructural study of the ontogeny and differentiation of pollen inPodocarpus macrophyllus D. Don (1970)
    Springer
    Protoplasma 71 (1970), S. 1-37 
    Details
    ISSN: 1615-6102
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Male cones ofPodocarpus macrophyllus D. Don enter a period of dormancy lasting almost a year after the differentiation of archesporial tissue. The cell walls of the sporogenous and tapetal cells are different in composition from those of the cells comprising the wall of the microsporangium. The walls of tapetal cells undergo complete dissolution but the naked protoplasts do not invade the cavity of the microsporangium, and eventually degeneratein situ. Sporopollenin-containing bodies are formed on the tapetal plasmalemma although no specific tapetal organelles can be singled out as sites of synthesis of sporopollenin precursors. The original walls of the microspore mother cells are broken down completely and replaced by a thin callose-like wall. No cytomictic channels are formed prior to or during early meiosis. The outer nuclear membrane of the sporogenous cells forms numerous vesicles which likely play an important role in preparing the cell for meiosis and in the breakdown of the original sporogenous cell wall and the formation of the new wall. Pronounced evaginations and invaginations of the nuclear envelope during the tetrad stage are seen which again indicate vital nucleo-cytoplasmic exchange at the time when species specific sexine layer is being laid down. The microspore protoplast synthesizes a portion of sporopollenin precursors. Sexine and part of nexine I are laid down during the tetrad stage on lamellae of unit membrane dimensions while nexines II and III are formed after the dissolution of the tetrads by the coalescence of small, electron dense particles. Cells of the male gametophyte are initially separated from each other by distinct cell walls often traversed by plasmodesmata. Mature pollen grains have appreciable reserves of protein, lipid and starch. Results of histochemical and scanning electron microscopical observations are also reported and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01294301
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  • 8
    Electronic Resource
    Electronic Resource
    Microcyst formation in the plasmodial slime moldDidymium iridis (1982)
    Springer
    Protoplasma 112 (1982), S. 81-91 
    Details
    ISSN: 1615-6102
    Keywords: Didymium iridis ; Microcyst-encystment ; Ultrastructure ; Differentiation ; Myxomycete
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Myxamoebae ofDidymium iridis were removed from the bacterial food source and induced to encyst by transfer to 10 mM phosphate buffer. After 24 hours of induction approximately 90% of the myxamoebae had differentiated into microcysts. The kinetics of encystment were not significantly affected by pH or osmolarity of the encystment medium. Early stages of encystment were distinguished by the appearance of autophagic vacuoles and an extracellular “slime-like” sheath. The outer wall layer, consisting of dense fibrils, was unevenly deposited after 4 hours. An electron-lucent, second wall layer appeared between 5–10 hours followed by a densely packed, third wall layer adjacent to the plasma membrane. Wall formation appeared to involve smooth-membraned vesicles of possible Golgi origin. The vesicle contents and outer wall layer reacted with the periodic acid-silver methenamine stain for polysaccharide. The density of intramembrane particles of the protoplasmic fracture face increased during encystment with a gradual formation of aggregates of particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280218
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  • 9
    Electronic Resource
    Electronic Resource
    The freeze-fractured structure of spermatocyte dictyosome-like structures (1987)
    Springer
    Protoplasma 138 (1987), S. 62-64 
    Details
    ISSN: 1615-6102
    Keywords: Freeze-fracture ; Diotyosom-like structures ; Spermatocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Guinea pig spermatocytes were fixed in glutaraldehyde, frozen in freon 22 cooled by liquid nitrogen, and then fractured to show the subcellular component previously identified as lddictyosome-like structure” (DLS). The DLS membranes had fewer particles than those of the Golgi apparatus. Moreover, the DLS saccules were without fenestrae which were common to Golgi apparatus cisternae. These results further confirm that the DLS are unique subcellular components of mammalian testes, and may prove useful in determining the etiology and function of DLS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281186
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  • 10
    Electronic Resource
    Electronic Resource
    Amyloplasts from cortical root cells of Spiranthoideae (Orchidaceae) (1993)
    Springer
    Protoplasma 172 (1993), S. 49-55 
    Details
    ISSN: 1615-6102
    Keywords: Amyloplast ; Cortex ; Orchidaceae ; Root ; Spiranthoideae ; Spiranthosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cortical root cells of orchids belonging to subfamily Spiranthoideae contain globular organelles which, through chemical tests and examination with both light, scanning, and transmission electron microscopes, appear to be unique in Orchidaceae and unreported in plants in general. It is suggested these are specialized amyloplasts (spiranthosomes) and with other features may serve to characterize the spiranthoid orchid subfamily.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403721
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