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  • 1970-1974  (186)
  • 1890-1899
  • 1973  (186)
  • Biochemistry and Biotechnology  (106)
  • Ultrastructure  (80)
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Materialart
Erscheinungszeitraum
  • 1970-1974  (186)
  • 1890-1899
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Electron microscopic visualization of proteoglycans and collagen in bovine costal cartilage (1973)
    Springer
    Calcified tissue international 13 (1973), S. 83-92 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Proteoglycan ; Collagen ; Cartilage ; Electron Microscopy ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé L'élimination de protéoglycans solubles de coupes de cartilage costal de boeuf, par extraction dans une solution de 4M d'hydrochlorure de guanidinium, permet de mettre en évidence des quantités abondantes de collagène dispersé et désagrégé dans la matrice. Les protéoglycanes, résistants à l'extraction, sont visibles sous forme de granules concentrés dans les régions périlacunaires. Les granulations plus importants des protéoglycanes semblent venir du chondrocyte. Dans la matrice, éloignée des chondrocytes, ces granules deviennent plus étroites. Un composant non granulaire “amorphe” masque les fibres de collagène, de telle sorte qu'elles sont difficilement visibles dans le cartilage intact.
    Kurzfassung: Zusammenfassung Die löslichen Proteoglycane wurden mittels Extraktion in 4 M Guanidinhydrochlorid aus Rippenknorpelschnitten des Rindes entfernt. Dies erlaubte die Sichtbarmachung von großen Mengen von verstreuten und auseinandergerissenen Collagen in der Matrix. Die Protoglycane, welche sich nicht extrahieren lassen, erscheinen als kleine, in den perilacunären Regionen konzentrierte Körnchen. Die großen Proteoglycan-Körner scheinen in den Chondrocyten zu entstehen. Sobald sie sich in die Matrix, außerhalb der Chondrocyten, verlagern, werden die Körner kleiner. Ein nicht-granulärer, „amorpher” Bestandteil verhüllt die Collagenfasern, so daß diese im intakten Knorpel nicht deutlich gesehen werden können.
    Notizen: Abstract Removal of the soluble proteoglycans from slices of bovine costal cartilage by extraction in 4 M guanidinium hydrochloride permitted the visualization of abundant amounts of dispersed and disaggregated collagen in the matrix. Proteoglycans which are resistant to extraction are seen as small granules which are concentrated in the perilacunar regions. Large proteoglycan granules appear to originate in the chondrocyte. As they come to occupy positions in the matrix distant from the chondrocyte, the granules become smaller. A non-granular, “amorphous” component masks the collagen fibers so that they cannot be readily seen in the intact cartilage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02015399
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  • 2
    Digitale Medien
    Digitale Medien
    Ultrastructural aspects of the preattached pig embryo: Cleavage and early blastocyst stages (1973)
    Springer
    Anatomy and embryology 143 (1973), S. 95-114 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Cleavage stages ; Blastocyst ; Pig ; Nucleus ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural observations of morphological changes in nuclei and cytoplasm of pig embryos during cleavage and early blastocyst stages are presented. Compact nuclear bodies (nucleosphaeridies) are demonstrable in the cleavage stages, and occasionally in the inner cell mass of blastocysts. The transformation of nucleosphaeridies leading to the formation of a peripheral network are usually found at the eight-cell stage. In morula, nucleoli make their first appearance as clearly distinguishable morphological entities. A marked disorganization of nuclear envelope is observed near to the cytoplasmic annulate lamellae (CAL) indicating a possible process of transformation of the former to the latter. During premorula stages cytoplasmic organelles (Golgi complex, endoplasmic reticulum, and CAL) are predominantly concentrated around the nucleus. CAL associated with fibrillogranular material similar to the material of the nucleoplasm occur in juxtanuclear positions. In the two-cell stage, degenerating paternal mitochondria are observed. In the morula the number of spherical mitochondria fell while that of elongated mitochondria increase. The trophoblast cells of the blastocyst stage contain cytoplasmic microfilaments which are closely associated with cell organelles, particularly the desmonsomes. Structurally changed mitochondria near the yolk globules and inclusion bodies of various morphology are found. A basal lamina is discernible parallel to the trophoblast layer facing the blastocoel. The observations are discussed in relation to physiological phenomena known to occur during embryogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00519913
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  • 3
    Digitale Medien
    Digitale Medien
    Uterine stromal morphology of the spayed, virgin rat when prepared with progesterone and oestrogen for implantation (1973)
    Springer
    Anatomy and embryology 141 (1973), S. 161-169 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Rat ; Uterus ; Stroma ; Ultrastructure ; Sex steroids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effect of progesterone and oestrogen on the central uterine stroma has been examined in order to analyze what changes occur when the uterus is hormonally prepared for implantation. Both progesterone and oestrogen, when given separately, cause nucleolar enlargement and growth of the granular endoplasmic reticulum. However, after progesterone treatment the nuclei are large and spherical whereas they are spindle-shaped after oestrogen treatment. When oestrogen is administered to the progesterone-treated rat little change occurs in the stromal morphology. There is little morphological support to the view that oestrogen acts on the stroma to increase endometrial sensitivity. Further, progesterone seems to stimulate the synthesis of RNA and of cellular protein only in the stromal cell while oestrogen has a similar effect in all cell types of the uterus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00519883
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  • 4
    Digitale Medien
    Digitale Medien
    Licht- und elektronenmikroskopische Untersuchungen an den peritubulären Zellen des Schweinehodens während der postnatalen Entwicklung (1973)
    Springer
    Anatomy and embryology 143 (1973), S. 49-64 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Testicular peritubular cells ; Boar ; Postnatal development ; Ultrastructure ; Contractility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Membrana propria der Hodentubuli des Schweines zeigt einen deutlichen Schichtenbau: Auf die Basalmembran des Tubulusepithels (a) folgen eine nicht-celluläre Lage mit Kollagenfibrillen (b), die von einer inneren (c) und einer äußeren (e) Basalmembran umhüllten peritubulären Zellen (d) und dann das intertubuläre lockere Bindegewebe (f). Die ausdifferenzierten peritubulären Zellen haben viele morphologische Merkmale mit glatten Muskelzellen gemeinsam. So besitzen sie Plasmalemmeinbuchtungen in Form pinocytotischer Bläschen sowie eine große Anzahl von Filamenten mit einem Durchmesser von 60–70 Å, welche über elektronendichte Strukturen an der Innenseite des Plasmalemms befestigt sind. Ein Golgi-Apparat, rauhes endoplasmatisches Reticulum, Mitochondrien und Mikrotubuli bevorzugen eine kernnahe Position. Im Gegensatz zu den Verhältnissen bei anderen Species sind viele charakteristische Eigenschaften der peritubulären Zellen schon vor der Pubertät ausgebildet. Die Filamente können bereits am 4. Tag als feines Netzwerk beobachtet werden, sie erfahren am 25. Tag eine starke Vermehrung und sind von nun an regelmäßig orientiert. Auch andere Befunde sprechen dafür, daß die peritubulären Zellen um den 25. Tag eine gesteigerte Aktivität entfalten. Die histochemisch nachgewiesenen Konzentrationen von alkalischer Phosphatase, Adenosintriphosphatase und Glucose-6-phosphatase erreichen zu diesem Zeitpunkt die hohen Werte, die auch für die weitere Entwicklungsphase und die ausdifferenzierten peritubulären Zellen typisch sind. Pinocytotische Bläschen erscheinen in größerer Anzahl ab dem 97. Tag. Mit dem 140. Tag sind die peritubulären Zellen morphologisch ausdiffrenziert.
    Notizen: Summary The boundary tissue of the porcine testicular seminiferous tubule (membrana propria) exhibits a distinct stratification: the basement lamina of the tubular epithelium (a) is followed by a non-cellular layer with collagen fibrils (b), the peritubular cells (d) with an inner (c) and outer (e) basement lamina and finally the intertubular loose connective tissue (f). Fully developed peritubular cells have many morphological features in common with smooth muscle cells, for instance inpocketings of the plasmalemma (pinocytotic vesicles) and a great number of filaments measuring 60–70 Å in diameter. These filaments are fixed at the inner side of the plasmalemma by means of electron-dense structures. The Golgi apparatus, rough endoplasmic reticulum, mitochondria and microtubules prefer a juxtanuclear position. In contrast that is seen in other species the porcine peritubular cells develop many of their characteristic features before puberty. In samples of the 4th day a fine network of filaments is already visible within the cytoplasm. These filaments are strongly augmented at the 25th day, and from now on they are arranged in a regular fashion. Other findings, also, underline an increased activity of the peritubular cells around day 25. At that time the concentrations of histochemically demonstrated alkaline phosphatase, adenosine triphosphatase and glucose-6-phosphatase reach the high levels typical for the stages of further development and the fully differentiated cells. Pinocytotic vesicles appear in great numbers from day 97. At the 140th day the morphology of the porcine peritubular cell is completely developed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00519910
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  • 5
    Digitale Medien
    Digitale Medien
    The early development of the median thyroid gland of the mouse (1973)
    Springer
    Anatomy and embryology 139 (1973), S. 319-336 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Fetal thyroid ; Microfilaments ; Lysosomes ; Acid phosphatase ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The mesobranchial area and the median thyroid anlage of embryonic albino mice were investigated from the somite stage 4 to 40 (81/2–10 days of gestation). In stage I (5–25 somites), there is an unequal growth and differentiation of the epithelium in the floor of the pharynx, whereby a mesobranchial area with a stratified or pseudostratified epithelium is formed. This area is distinct from the remaining pharyngeal epithelium, among other things by an apical microfilament system in the superficial epithelial cells. It is found just basal to a row of plump cytoplasmic protrusions, which extend into the lumen of the pharynx. In stage II (26–40 somites), the cranial part (median thyroid anlage) of the mesobranchial area thickens in relation to the caudal part and grows down into the underlying mesenchyme. The filament system is concentrated in the superficial cell layer of the median thyroid anlage at the beginning of stage II and disappears during downgrowth. In both stages, but most pronounced in stage II, there is a population of 0.1–5 μ intracellular bodies, which occasionally contain the remains of organelles. The larger bodies, which often contain the remains of nuclei, are usually found peripherally while the smaller ones are more evenly distributed. Acid phosphatase can often be demonstrated histochemically in small bodies, while larger bodies are usually without reaction. Cells with pycnotic nuclei and/or degenerated cytoplasmic components are regularly found. Acid phosphatase can also be demonstrated in Golgi complexes and surrounding vesicles. Basal to the epithelium, bodies are occasionally found which may possibly have been extruded from that tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00519971
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  • 6
    Digitale Medien
    Digitale Medien
    Electron microscopic study of the muscle changes in diabetic amyotrophy (1973)
    Springer
    Acta neuropathologica 24 (1973), S. 331-339 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Diabetic Amyotrophy ; Muscle Biopsy ; Ultrastructure ; Type II Fibre Atrophy ; Partial Denervation ; Neurogenic Atrophy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Seven cases of diabetic amyotrophy were investigated by histochemistry and electron microscopy of biopsied muscles. Type II fibre atrophy of various grades was observed in the proximal atrophic muscles. Various changes of Z-band were observed in type II atrophic muscle fibres. In addition, mitochondrial changes, accumulation of glycogen, thickening of the capillary basement membrane and changes in the intramuscular nerves were also observed, both in the proximal and distal muscles. Some impaired motoneuron innervation of proximal muscles as well as distal muscles in a poorly controlled diabetic condition is suspected in “diabetic amyotrophy”.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685588
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  • 7
    Digitale Medien
    Digitale Medien
    Ultrastructure of a sacrococcygeal chordoma (1973)
    Springer
    Acta neuropathologica 25 (1973), S. 27-35 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Ultrastructure ; Chordoma ; Sacrococcygeal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of a sacrococcygeal chordoma is presented. The cells vary in their size and electron density but are thought to have a common origin. The nuclei presented prominent nucleoli and intranuclear bodies. Centrioles were seen in some of the cells. The rough endoplasmic reticulum was prominent and in most cells was very distended and corresponded to the intracellular vacuoles of light microscopy. The contents of the rough endoplasmic reticulum and the abundant extracellular substance were similar.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00686855
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  • 8
    Digitale Medien
    Digitale Medien
    Ultrastructural analysis of phospholipase a induced changes in membranes of synaptic regions in rat motor cortex (1973)
    Springer
    Experimental brain research 16 (1973), S. 400-409 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Ultrastructure ; Synapses ; Brain cortex ; Phospholipase A ; Membranes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effect of purified Naja nigricollis phospholipase A on slices from motor cortex from rat brain was analysed at an ultrastructural level. Samples stabilized directly with glutaraldehyde were compared with samples incubated in buffer with or without enzyme. Plasma membranes of nerve terminals, synaptic contact regions and synaptic vesicles were the main parameters studied. As judged by the electron microscopic technique the synaptic areas show a high resistance to the enzyme treatment. The intercellular space of the synaptic cleft seems unaltered. At the highest concentrations of the enzyme an increased density is noticed at the presynaptic part of the membrane. The extracellular space widens and nerve terminals and mitochondria become distended with increasing enzyme concentrations. The membranes all through the tissue appear ruptured to small pieces and at the highest enzyme concentrations used, altered in their structural organization. Quantitative analysis shows that the number of synaptic vesicles per unit surface area decreases, while ruptures of the plasma membranes of nerve terminals increase in number with increasing enzyme concentrations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233431
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  • 9
    Digitale Medien
    Digitale Medien
    Ultrastructure of herpes simplex virus infection of the nervous system of mice (1973)
    Springer
    Acta neuropathologica 26 (1973), S. 285-299 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Herpes simplex Virus ; Ultrastructure ; Viral Infection ; Virus-Host Interaction ; Nervous System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The nervous system and small intestine of mice infected with herpes simplex virus were examined by electron microscopy from the viewpoint of virus-host interaction. The host cells examined included the neuron, astrocyte, oligodendrocyte, and Schwann cell. The susceptibility of the latter was not less than that of the neuron. The endothelial cell, perineural fibrocyte and smooth muscle cell were also host cells. Replication of herpes virus in the nervous system was proven to be identical to that occurringin vitro; initial reproduction of nucleocapsids in the nucleus and subsequent maturation at the nuclear membrane with envelope formation, followed by discharge into the cytoplasmic reticular cavities and finally release from the host cell. Inconsistency in the distribution of virus particles and viral antigen was chiefly concerned with the host cell nucleus and the glial cytoplasm. Herpes virions, though few, were identified in the axons of peripheral nerves, and in the periaxonal space of myelinated fibres in the brain and the nerve ganglia. Virions were present in tiny vesicles in the perikarya or as naked particles. In the distal parts of peripheral nerve, there was marked dissociation in the amount of virions between Schwann cells and the axon. The significance of the endoneural space and the axon in the neural speread of infection is discussed briefly.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688077
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  • 10
    Digitale Medien
    Digitale Medien
    The ultrastructural arrangement of thrombosthenin in glycerol extracted thrombocytes (1973)
    Springer
    Cell & tissue research 138 (1973), S. 557-567 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Thrombocytes ; Thrombosthenin ; ATP ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of glycerol extracted thrombocyte models was studied before and after incubation with ATP and under the influence of Salyrgan as inhibitor of contraction. The contractile system of the thrombocytes—thrombosthenin—consists of a spatial network of 50 Å wide thrombosthenin A and 100–120 Å wide thrombosthenin M filaments. At rest, the contractile system is arranged in a marginal zone. The ATP-induced contraction led to a concentric condensation of the network which resulted in a central cluster of cell organelles and at a later stage, disruption of the plasma membrane and release of the thrombocyte granules. All these changes which also occur during the formation of the hemostatic plug in vivo are therefore attributed to the reaction of the contractile protein.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00572296
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  • 11
    Digitale Medien
    Digitale Medien
    Corticotrophic cells in the rostral zone of the pars intermedia and in the adjacent neurohypophysis of the rat and mouse (1973)
    Springer
    Cell & tissue research 136 (1973), S. 97-110 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypophysis ; Mouse, rat ; Pars intermedia, rostral zone ; Corticotrophic cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the mouse, the rostral zone of the pars intermedia is almost exclusively composed of typical corticotrophic cells. They are located around and even within the neural stalk, at the level of transition between stalk and neural lobe. In the rat, the corticotrophic cells of the rostral zone are found in scattered islets among the MSH producing cells, and also in the neural lobe. In both the rat and mouse, these cells are in direct contact with various types of nerve terminals. Synaptoid contacts with aminergic and neurosecretory nerve fibers are observed. Furthermore they are also closely related to the hypophysial portal vessels. Following adrenalectomy, the cells located in the neurohypophysis always react more intensely than tose in the rostral zone. The functional significance of these corticotrophic cells which are subject to both humoral and neural regulation remains as yet hypothetical. Their participation in neurogenic stress response seems probable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307682
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  • 12
    Digitale Medien
    Digitale Medien
    Quantitative data on the fine structural organization of the palisade zone of the median eminence (1973)
    Springer
    Cell & tissue research 136 (1973), S. 111-120 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Rat ; Granular vesicles ; Ultrastructure ; Quantitative evaluation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In order to characterize different sub-zones in the palisade zone of the rat median eminence, quantitative ultrastructural parameters were applied to brains fixed in aldehyde-osmium tetroxide. The palisade zone has been subdivided in 4 successive sub-zones. Increasing numbers of granular vesicles (GV), especially those smaller than 110 nm, are observed from dorsal to ventral sub-zones. There also are more GV per unit area of nervous tissue in the perivascular than in the more dorsal sub-zones. The individual nerve profiles exhibit a larger size in the perivascular layer than in the more dorsal areas, whereas the number and size of nerve profiles devoid of vesicles diminish from dorsal to ventral. As a consequence more GV occur in the perivascular nerve profiles. In the GV containing nerve profiles the concentration of GV is, however, constant in the different sub-zones. A fluctuating size of the preterminal and terminal parts of the nerve fibres is suggested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307683
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  • 13
    Digitale Medien
    Digitale Medien
    Studies on the fine structure of the protozoan Cyclidium, with special reference to the mitochondria, pellicle and surface-associated bacteria (1973)
    Springer
    Cell & tissue research 139 (1973), S. 303-310 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Protozoa ; Bacteria ; Association ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of Cyclidium, including the cilia, kinetosomes, pellicle, microtubules and kinetodesmal fibers is similar to that recorded for other ciliates. Of special interest is the attachment of rod-shaped bacteria within the longitudinally directed shallow surface folds of the protozoan. Both the bacteria and the surface of Cyclidium seem to possess an outer coating of a sticky substance which upon contact holds the bacteria to the protozoan. The bacteria appear to be attached by only a relatively small area of their surfaces. A dense substance appears within the alveolus of the pellicle at the regions of the attachment of the bacteria. The association of the organisms is probably a temporary one, and it is unknown whether either organism is benefited or harmed by the association. The position of the mitochondria in Cyclidium is unusual in that they all lie flattened against the inner membrane of the pellicle, usually in a position directly opposite to that of the attachment of the bacteria to the surface, thus being separated from the bacteria by only the outer cell membrane and the pellicle. Whether or not this close topographical relationship is of significance is unknown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306587
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  • 14
    Digitale Medien
    Digitale Medien
    The effect of salinity acclimation on the ultrastructure of the gills of Gammarus oceanicus (Segerstråle, 1947) (Crustacea: Amphipoda) (1973)
    Springer
    Cell & tissue research 139 (1973), S. 311-318 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Gill ; Gammarus oceanicus ; Salinity acclimation ; Ultrastructure ; Mitochondria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Acclimation to low salinity induces changes in the ultrastructure of the gill cells of the marine euryhaline amphipod, Gammarus oceanicus. The gills are composed of a single cell type. In 100% artificial sea water, these cells contain moderate numbers of mitochondria which are randomly distributed in the cytoplasm. The plasma membrane is extensively invaginated at the apical, lateral, and basal surfaces. Acclimation to 20% artificial sea water induces a further invagination at the apical cell membrane to form an elaborate apical labyrinth. The extracellular spaces between the folds in the basal cell membrane dilate to 1500 Å or more. Mitochondria are more abundant and in many cells they undergo a change in conformation. The mitochondria are crowded into thin leaflets of cytoplasm between the dilated basal invaginations or into the narrow space between apical and basal cell membranes. Consequently, they lie in close contact with the plasma membrane over much of their surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306588
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  • 15
    Digitale Medien
    Digitale Medien
    Zur Feinstruktur des dorsalen Riesenfasersystems im Bauchmark des Regenwurms (1973)
    Springer
    Cell & tissue research 139 (1973), S. 351-368 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lateral giant cells ; Dorsal giant fibres ; Earthworm, Lumbricus terrestris L. ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Feinstruktur der segmental angeordneten Somata der dorsalen Riesenfasern im Bauchmark des Regenwurms Lumbricus terrestris L. (Günther, 1969) wird beschrieben und mit der Struktur anderer Neuronen von Vertebraten und Evertebraten verglichen. Die paarigen lateralen Riesenzellen (LRZ) sind im Gegensatz zu der unpaaren medianen Riesenzelle (MRZ) häufig multipolare Neuronen, die bis zu vier Faserfortsätze aufweisen können. Das perikaryale Cytoplasma zeigt helle und dunkle Areale. Organellen und andere Zelleinschlüsse finden sich ganz überwiegend in den dunklen osmiophilen Zonen und lassen regelmäßig eine bestimmte Anordnung erkennen. So ist häufig eine ringförmige Verteilung von Golgi-Feldern um den gelappten Kern vorhanden. Mitochondrien sind häufig in einem typischen „Axonhügel-Komplex“ angeordnet. Freie Ribosomen dominieren gegenüber membrangebundenen. Diese Neuronen sind reich an Glykogen, das oftmals ausgedehnte Felder einnimmt. Vereinzelt weisen die LRZ Faser-Soma-Synapsen auf.
    Notizen: Summary The structure of the segmentally arranged somata of the dorsal giant fibres Günther, 1969) in the ventral nerve cord of the earthworms Lumbricus terrestris L., is described. These neurones are compared with other neurones of invertebrates and vertebrates. The paired lateral giant cells (LGC) are often multipolar in contrast to the single unipolar median giant cell (MGC). Up to four fibres originate from each LGC. The dotted appearance of both these neurones (clear and dark perikaryal areas) is due to the regular distribution of osmiophilic strands of cytoplasm containing the majority of organells and other inclusions (e.g. endoplasmatic reticulum and ribosomes). The majority of ribosomes are not associated with membranes but are found scattered freely in the cytoplasm. A typical “axon hillock” with an accumulation of mitochondria is often found. The cells show large deposits of glycogen. Some of the LGC-somata have synaptic contacts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306591
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  • 16
    Digitale Medien
    Digitale Medien
    Die Anordnung der Ommatidien in der Retina der Biene (Apis mellifica L.) (1973)
    Springer
    Cell & tissue research 139 (1973), S. 567-582 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Compound Eye ; Apis mellifica ; Polarized light ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 1. Die Ausrichtung der Rhabdome ist in der Bienenretina nicht konstant. 2. Die Anordnung der exzentrischen Zellen in der Bienenretina ist ebenfalls nicht konstant, und es läßt sich keine symmetrische Verteilung dieser Zellen nachweisen. 3. Die Morphologie der Retina wird im Hinblick auf die Orientierung der Honigbiene nach dem Polarisationsmuster des vom blauen Himmel reflektierten Lichtes diskutiert.
    Notizen: Summary 1. The orientation of the rhabdoms shows no regularity within the retina of the honeybee. 2. The arrangement of the eccentric cells is also irregular within the retina of the honeybee. 3. The morphology of the retina is discussed regarding the ability of the honeybees to orient according to the pattern of the polarization of light reflected from the blue sky.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02028393
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  • 17
    Digitale Medien
    Digitale Medien
    Le Système Nerveux des Cténaires (1973)
    Springer
    Cell & tissue research 137 (1973), S. 223-250 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nervous system ; Ctenophores ; Nerve-net, Nervous concentration ; Synapses ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A subectodermal nerve-net is demonstrated in ten species of Ctenophores by means of either Methylene Blue vital staining or silver impregnation. There is no evidence of subendodermal nerve-net. The ectodermal nerve-net displays a characteristic polygonal pattern which is thought to result from morphogenetic events. Both bipolar and tripolar neurones occur. Three types of concentrations of nervous tissue are described: a) a high accumulation of nervous perikarya at the aboral sensory pole; b) a noticeable densification of the net along the eight meridional ciliary strands of every species, and around the lips of Beroidea; c) in the Cydippids Pleurobrachia and Hormiphora two thick strands of fibers and neurones interconnecting the aboral organ and the tentacles: the tentacular nerves. Ultrastructural evidence is given for the presence of nervous elements under and amidst ectodermal epithelial cells. Three features allow the recognition and characterization of neurites and neurones: a) numerous clear and/or granulated vesicles; b) microtubules in variable amounts; c) frequent and highly differentiated synaptic contacts. The very peculiar arrangement of the presynaptic elements is observed in all the species of Ctenophores so far studied. These synaptic contacts suggest chemical transmission in the nerve-net. On the basis of ultrastructural evidence the author refutes the nervous nature previously attributed to the ciliated cells of the meridional grooves. A parallel is drawn between nervous systems of Cnidaria and Ctenophora.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307432
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  • 18
    Digitale Medien
    Digitale Medien
    Electron microscopy of dental enamel: Analysis of crystal lattice images (1973)
    Springer
    Cell & tissue research 137 (1973), S. 271-280 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Dental enamel ; Rat ; Ultrastructure ; Crystallography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Thin sections of rat incisor enamel were studied with the electron microscope. Fringe patterns having repeat periods in the range 3.1–8.2 Å were seen in individual enamel crystals. These images were interpreted as representing the resolution of corresponding planes in the hydroxyapatite crystal lattice. The lattice spacings and interplanar angles were identified by comparing the observations with available data derived from X-ray diffraction analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307434
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  • 19
    Digitale Medien
    Digitale Medien
    Ultrastructure of the pars distalis of the lizard Anolis carolinensis with special reference to the identification of the gonadotropic cell (1973)
    Springer
    Cell & tissue research 137 (1973), S. 293-312 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypophysis ; Pars distalis ; Lizard ; Gonadotropic cell ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Five categories of granulated cells were distinguished by their ultrastructural features, and quantitative analyses were made of the pars distalis cells in normal and castrated lizards. The gonadotropin-producing cell was identified on the basis of its uniform distribution in the gland as well as from cytological changes resulting from castration. The secretory granules of the gonadotropic cell vary in size (100–500 mμ) and density, and lipid bodies are commonly present. Following castration, the endoplasmic reticulum proliferates, forming many small, rough-surfaced, dilated cisternae which do not coalesce greatly as in other vertebrate species. Degranulation is accompanied by hypertrophy and hyperplasia of the mitochondria and by the appearance in the cytoplasm of conspicuous clusters of microfilaments. The designated gonadotropic cell was the only class of secretory cell showing consistent changes following three weeks of castration. In addition to the uniformly distributed gonadotrope cell, two secretory cells occur mainly in the rostral half of the gland, and two in the caudal half. Tentative identification of the cell types is discussed in the light of available information on the localization of the hormones in the pars distalis of this species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307205
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  • 20
    Digitale Medien
    Digitale Medien
    Smooth muscle-like cells in ovaries of the hamster and gerbil (1973)
    Springer
    Cell & tissue research 140 (1973), S. 1-8 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Smooth muscle ; Hamster ; Gerbil ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Smooth muscle-like cells are present in thecae externae, corpora lutea, and interstitial tissue of hamsters and gerbils. The smooth muscle-like cells, as examined by electron microscopy, are fusiform with central nuclei; the cytoplasm contains numerous myofilaments, dense bodies, micropinocytotic vesicles, and dense accumulations of glycogen-like particles. In addition to the smooth muscle-like cells, fibroblasts and cells that have characteristics of both fibroblasts and smooth muscle are located in the thecae externae of both species. There is no ultrastructural evidence of innervation in the theca folliculi, corpora lutea, or interstitial tissue of either species. A possible function for the smooth muscle-like cells is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307055
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  • 21
    Digitale Medien
    Digitale Medien
    Associations jonctions-organites cellulaires dans le foie néo-natal de souris (1973)
    Springer
    Cell & tissue research 140 (1973), S. 77-89 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Intercellular junctions ; Neonatal liver ; Mouse ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Au cours du passage de la vie foetale à la vie postnatale, on note, dans le foie de souris, l'apparition d'associations jonctions-organites cellulaires. Celles-ci cont de deux types: associations desmosomes-organites et associations nexus-organites. 1.Associations nexus-organites. Le long de la «gap junction» sont étroitement accolés, uni ou bilatéralement, divers organites: mitochondrie(s), subsurface cisterna(e), peroxysome(s) ou lysosome. Ces associations n'apparaissent qu'entre le 21ème jour de la gestation et le ler jour post-natal, période à partir de laquelle ils disparaissent au profit d'associations desmosomes-organites cellulaires. Un nouveau type de structure s'associe dans le foie aux membranes plasmatiques: il s'agit des saccules ergastoplasmatiques ou subsurface cisternae. 2.Associations desmosomes-organites. Dans ces complexes, les tonofilaments desmosomiques entrent étroitement en contact avec la paroi des organites cellulaires associés: mitochondrie ou peroxysome. Déjà présents au 13ème jour de la gestation, ces structures s'observent plus fréquemment à partir du ler jour post-natal. La signification de ces associations reste à déterminer, d'autant plus que leur présence a déjà été signalée dans de trés nombreux tissus. Quelques hypothèses sont présentées.
    Notizen: Summary During the transition between the fetal and postnatal periods associations between cell junctions and cell organelles appear in the liver of the mouse. These associations are of two types: desmosome-organelle and nexus-organelle. 1.Nexus-Organelles Association. Unilaterally or bilaterally, various organelles — mitochondria, cysternae, microbodies or lysosomes — adhere tightly along the gap. These associations appear only between the 21st day of gestation and the first postnatal day. Thereafter they gradually disappear and are replaced by desmosome-organelle associations. Another type of structure — ergastoplasmic saccules or cisternae of rough endoplasmic reticulum — become associated with the cell membrane. 2.Desmosome-Organelle Associations. In these complexes the desmosomal microfilaments are in close contact with membranes of the associated organelles — mitochondria or peroxysomes. The associations, which exist as early as the 13th day of gestation increase after the first postnatal day. The significance of these associations remains to be ascertained, especially since they occur in many other tissues. A few hypotheses are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307059
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  • 22
    Digitale Medien
    Digitale Medien
    Fine structural alterations with age in the fat body of the adult male housefly, Musca domestica (1973)
    Springer
    Cell & tissue research 140 (1973), S. 169-175 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Fat body ; Housefly ; Aging ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fat body of the adult housefly is composed of two types of cells, the lipid-and glycogen-rich fat body cells and the oenocytes. A comparison of the fine structure of the abdominal fat body in 4-day old and 31–35 day old male houseflies indicated an increase in lipid and a decrease in glycogen content in the fat body cells of old flies. Oenocytes of old flies exhibit deteriorative alterations with an accumulation of secondary lysosomes. Both fat body cells and oenocytes in senile flies are ingested by hemocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306692
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  • 23
    Digitale Medien
    Digitale Medien
    L'innervation du lophophore chez le Bryozoaire chilostome Electra pilosa (L.) (1973)
    Springer
    Cell & tissue research 140 (1973), S. 217-234 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Tentacles ; Electra pilosa ; Nerves ; Bielschowsky technique ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Le trajet des grands nerfs de la couronne tentaculaire et la structure du collier nerveux péripharyngien dont ils se détachent, ont été précisés chez Electra pilosa par des imprégnations argentiques in toto selon la technique de Bielschowsky et par une étude d'ultrastructure. Chaque tentacule est innervé par quatre faisceaux nerveux, dépourvus d'envelope gliale, qui courent entre l'épithélium et l'assise collagène qui délimite le canal tentaculaire interne; trois sont rassemblés sous les trois rangées cellulaires épithéliales de l'arête orale du tentacule et le quatrième est médian-dorsal. Les cellules épithéliales orales-latérales, par leur forme pédonculée, par la densité de leur cytoplasme, par leur cil unique et par leur relation topographique et cytologique avec les nerfs tentaculaires sous-jacents, présentent des adaptations structurales telles qu'il parait probable qu'elles assurent une fonction tactile. L'examen du collier péripharyngien montre son caractère organisé et la complexité des connexions qui coordonnent l'ensemble des tentacules et relient le lophophore à d'autres secteurs de l'innervation.
    Notizen: Summary The pathway of the tentacle nerves and the organisation of the peripharyngial nervous belt from which they arise, have been studied in Electra pilosa by silver stained whole mounts (Bielschowsky technique), and by ultrastructural investigation. Each tentacle is innervated by four nervous fascicles without any differentiated glial sheath, running between the epithelium and the collagen layer which surrounds the muscles and the peritoneal cells in the internal tentacle canal. Three nerves are gathered underneath the three rows of epithelial cells forming the oral edge of the tentacle. The fourth nerve is in medio-dorsal location. The oral epithelial cells show such ultrastructural adaptations in their general shape, in the density of their cytoplasm, in their ciliary apparatus reduced to a single cilium and in their close topographical and cytological relationship with the underlying tentacle nerves that it seems most probable they have a tactile function. The analysis of the pattern of the peripharyngial nervous belt shows a precise organisation and the intrication of the connections which coordinate the tentacles and link the lophophore set to other pathways of general innervation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306696
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  • 24
    Digitale Medien
    Digitale Medien
    Suppression of somatotrophs in growth hormone injected rats (1973)
    Springer
    Cell & tissue research 140 (1973), S. 309-314 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary Gland ; Rat ; Somatotropin ; Cellular Response ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The response of somatotrophs to large doses of purified bovine growth hormone was examined in uninephrectomized rats drinking 1% sodium chloride in an attempt to prolong the action of the hormone. Growth hormone produced a triphasic response in the ultrastructure of somatotrophs. Uninephrectomy and salt alone induced no changes in somatotrophs as compared to unoperated animals consuming tap water. In the first phase (3 days) the cross sectional area of the cell increased, the size of the largest granule per cell as well as the number of granules per cell increased significantly. All these parameters then reached control level after 7 days of injections during a second phase. Suppression of somatotrophs by exogenous growth hormone was evident by 16 days (third phase) when the area of the cell, the size of the largest secretory granule as well as the number of granules per cell all decreased significantly. Somatotrophs apparently did not react to suppression by a lysosomal mechanism inasmuch as no increase in the number of lysosome-derived structures was seen even at 16 days.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307020
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  • 25
    Digitale Medien
    Digitale Medien
    Ultrastructural aspects of mouse cecal epithelium (1973)
    Springer
    Cell & tissue research 140 (1973), S. 445-449 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cecum, Colon ; Mouse ; Glycocalyx ; Intestinal microorganisms ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the cecal epithelium of the mouse resembles that of more distal parts of the colon. A brief discussion is presented of the possible significance of apical cytoplasmic granules to the glycocalyx and of the close association of microorganisms with the lining epithelium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306671
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  • 26
    Digitale Medien
    Digitale Medien
    Fine structure of the adenohypophysis in immature sockeye salmon, Oncorhynchus nerka (1973)
    Springer
    Cell & tissue research 140 (1973), S. 459-471 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adenohypophysis ; Sockeye salmon ; Cell types ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the secretory cells of the adenohypophysis of juvenile sockeye salmon was investigated. Pituitary glands were collected from immature fish transferred experimentally to sea water and subsequently returned to fresh water. The rostral pars distalis contained three cell types: ACTH cells, prolactin cells, and non-secretory cells. The prolactin and non-secretory cells were joined together in the form of follicles by desmosomes and they both had cilia and microvilli projecting into the follicle lumen. Various follicular structures such as lumen, multivesicular structures, and peripheral basement membrane are discussed as possible sites of prolactin cell granule release. The columnar ACTH cells were found at the junction of the rostral pars distalis and the neurohypophysis. The cytoplasmic granules in these cells were characteristically separated from their limiting membrane by a clear space. Multivesicular structures were also found in association with this cell type. The caudal pars distalis also contained three cell types: one acidophil (putative somatotrop) and two basophils (putative thyrotrops and gonadotrops), all of which were similar to those described in adult fish. The pars intermedia contained only one cell type. They appeared to be active cells and were characterized by containing membrane-bounded granules similar to those found in the ACTH cells. Changes in ambient salinity had no apparent effect on any cell type described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306673
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  • 27
    Digitale Medien
    Digitale Medien
    Fine structure of eyespots in tornarian larvae (Phylum: Hemichordata) (1973)
    Springer
    Cell & tissue research 142 (1973), S. 89-102 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Photoreceptors ; Larva ; Hemichordate ; Ultrastructure ; Evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The eyespots of tornariae of enteropneusts (Ptychodera flava from Hawaiian waters and an unknown species from southern California) were studied by electron microscopy. An ocellus is composed of two types of cells: sensory and supportive. The former is characterized by a bulbous cilium (with 9+2 axoneme) at its distal end, one or sometimes two arrays of microvilli from its sides below the cilium, and a basal axon. The latter features large, clear vesicles which presumably contained the reddish-orange pigment seen in the ocellus of a living larva. Five-day old tornariae of P. flava are positively phototactic. Both cilium and microvilli may function as photoreceptors. The tornarian ocellus studied is compared with eyespots of other invertebrates, and the evolutionary significance of its putative photoreceptors is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306706
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  • 28
    Digitale Medien
    Digitale Medien
    La spermiogenèse d'Albula vulpes (L. 1758) (Poisson Albulidae) (1973)
    Springer
    Cell & tissue research 142 (1973), S. 171-192 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Teleost ; Albula vulpes ; Flagella ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé La jeune spermatide possède un noyau arrondi, un diplosome proche de la membrane cellulaire auquel sont associées des formations paracentriolaires; une mitochondrie unique est disposée entre le diplosome et le noyau. Au cours de l'évolution de la spermatide, le noyau s'allonge latéralement, son grand axe étant perpendiculaire à l'axe flagellaire; la mitochondrie migre à l'extrémité latérale du noyau; le centriole distal donne un flagelle de type 9+0; le centriole proximal se prolonge le long du noyau puis sort de la cellule sous la forme d'un pseudo-flagelle. Le prolongement centriolaire est constitué de triplets classiques et de doublets d'un type particulier que nous avons appelés «doublets A–C». Les auteurs signalent la similitude des spermatozoïdes de cet Elopiforme avec les spermatozoïdes d'Anguilliformes ce qui serait en faveur de la proposition de Greenwood et al. de rassembler ces téléostéens dans le super-ordre des Elopomorphes.
    Notizen: Summary The early spermatid possesses a round nucleus and a diplosome which is close to the cellular membrane and with which paracentriolar formations are associated; a sole mitochondrion is located between the diplosome and the nucleus. During the spermatid evolution, the nucleus is laterally elongated, its main axis being perpendicular to the flagellar axis; the mitochondrion migrates towards the lateral end of the nucleus; the distal centriole is extended along the nucleus, then leaves the cell as a pseudoflagellum. This centriolar extension is made up of regular triplets and of a particular type of doublets that we have called “A–C doublets“. The authors call attention to the similarity between the spermatozoa of this Elopiforme and the spermatozoa of the Anguilliformes. This observation favours Greenwood et al.'s proposition, to place these teleost into the super-order of Elopomorpha.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307031
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  • 29
    Digitale Medien
    Digitale Medien
    Feinstruktur der Luteinzellen des Meerschweincheneierstocks während der Schwangerschaft und des Zyklus (1973)
    Springer
    Cell & tissue research 142 (1973), S. 525-537 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lutein cells ; Guinea pig ; Sexual cycle ; Pregnancy ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Feinstructur der Luteinzellen des Meerschweinchens während Schwangerschaft (15., 35., 45., 50., 55., 63. und 2 Tage nach der Geburt) und Zyklus (9, 14, 16, 20 Tage nach der Ovulation) wurden elektronenmikroskopisch untersucht. In den aktiven Luteinzellen kann man konzentrisch um die Lipoidtropfen angeordnete Strukturen des agranulären endoplasmatischen Retikulum beobachten, die später durch Membranstrukturen des granulären endoplasmatischen Retikulum ersetzt werden. Die Mitochondrien sind rund und enthalten tubuläre Innenstrukturen, die Lipoidtropfen sind elektronenoptisch dicht. Während der Rückbildung des Corpus luteum setzt sich das endoplasmatische Retikulum aus ungeordneten Vesikeln und Tubuli zusammen, die Mitochondrien sind länglich oder verzweigt, die Lipoidtropfen elektronenoptisch hell. Die Bedeutung dieser feinstrukturellen Veränderungen in der Luteinzelle wird diskutiert.
    Notizen: Summary The fine structure of the lutein cells in guinea pigs corpora lutea of pregnancy (15th, 35th, 45th, 50th, 55th, 63th day and 2 days after birth) and during oestrous cycle (9, 14, 16, 20 days after ovulation) is described. During the active phase of the corpus luteum the formation of concentric whorls of agranular endoplasmic reticulum around lipid droplets is observed, but later the granular endoplasmic reticulum increases. In this stadium the mitochondria are round with tubulous cristae and the lipid droplets are increased in density. During the involution of the corpus luteum the endoplasmic reticulum does not form concentric whorls, the mitochondria are elongated, polymorphic, the lipid droplets have lower electron density. These ultrastructural changes in the lutein cells are discussed concerning the role of the cell organelles in the steroid synthesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306713
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  • 30
    Digitale Medien
    Digitale Medien
    Licht- und elektronenmikroskopische Untersuchungen an den Leydigzellen des Schweines während der postnatalen Entwicklung (1973)
    Springer
    Cell & tissue research 143 (1973), S. 207-227 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Testis interstitial cells ; Boar ; Postnatal development ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die postnatale Ontogenese der Hodenzwischenzellen des Schweins nimmt einen wellenförmigen Verlauf und läßt sich in 4 Phasen unterteilen. In der frühpostnatalen Proliferationsphase wandeln sich spindelförmige Zellen in polygonale Leydigzellen um. Dabei beginnt an einem Zellpol die Ausbildung des glatten endoplasmatischen Retikulums. Dieses Organell nimmt in der weiteren Entwicklung einen großen Teil des Zelleibes ein und bildet unregelmäßige Vesikel und konzentrisch geschichtete Zisternen. Es erfolgt eine Vermehrung der Mitochondrien, in ihnen entwickeln sich Tubuli. In der Phase der präpubertären Hypertrophie erreichen die Leydigzellen ihre größten Durchmesser (ca. 30 μm) und sind möglicherweise zu einer Steroidhormonproduktion befähigt. Da das glatte endoplasmatische Retikulum vornehmlich in der Zellperipherie, die übrigen Organellen bevorzugt im Zentrum liegen, sind die Zwischenzellen deutlich zoniert. Die Phase der präpubertären Regression ist durch ausgeprägte Zelldegeneration und Größenabnahme der überlebenden Zellen gekennzeichnet. In der Phase der pubertären Proliferation nehmen die Zwischenzellen erneut an Größe zu. Parallel hierzu vermehren sich Mitochondrien und glattes endoplasmatisches Retikulum. Beide Proliferationsphasen innerhalb der postnatalen Ontogenese werden durch das Auftreten zahlreicher Cytoplasmafilamente eingeleitet, deren Menge sich danach wieder verringert. Unabhängig von dem wellenförmigen Verlauf der Zwischenzellentwicklung ist die Ausbildung von Lysosomen, Microbodies, Mikrovilli, typischen Zellhaften und in der Zellperipherie gelegenen Polyribosomen. Die Leydigzellen sind von einer basalmembranähnlichen Struktur umgeben. Die Mitochondrien enthalten zu allen Zeiten durch elektronendichtes Material verkittete Tubuli.
    Notizen: Summary The postnatal development of porcine testicular interstitial cells proceeds in a wave-like manner and may be divided into four periods. In the period of early postnatal proliferation fusiform intertubular cells change into polygonal Leydig cells. This process starts with formation of smooth endoplasmic reticulum in one of the cell poles. Later the smooth endoplasmic reticulum is abundant and consists of irregular vesicles and concentrically arranged cisterns. Mitochondria increase in number and develop tubular cristae. In the period of prepubertal hypertrophy Leydig cells reach maximal size (approx. 30 μm) and possibly may be capable of androgen biosynthesis. The cells of this period exhibit two different zones, since the smooth endoplasmic reticulum prefers the periphery, the other organelles, however, occupy the central region of the cells. The period of prepubertal regression is characterized by cellular degeneration and diminuation of the surviving interstitial cells. In the period of pubertal proliferation an increase of Leydig cell size is accompanied by multiplication of mitochondria and development of smooth endoplasmic reticulum. Both periods of proliferation are initiated by appearance of numerous cytoplasmic filaments which subsequently decrease in number. Interstitial cells of all periods studied exhibit the following features: They possess lysosomes, microbodies, polyribosomes, microvilli and are surrounded by a kind of basement membrane. Cell connections appear as tight junctions and desmosome-like structures. The mitochondria contain closely packed tubules joined by electron dense material.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307479
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  • 31
    Digitale Medien
    Digitale Medien
    An ultrastructural study of the synaptic densities, nematosomes, neurotubules, neurofilaments and of a further three-dimensional filamentous network as disclosed by the E-PTA staining procedure (1973)
    Springer
    Cell & tissue research 143 (1973), S. 239-272 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nervous tissue ; Specific structures ; Nematosomes ; Neurofilaments ; Neurotubules ; Three-dimensional filamentous network ; E-PTA Stain ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary After the staining of nervous tissue with phosphotungstic acid in absolute ethanol (E-PTA), a selective opacification occurs at certain specific sites, while other structures, especially the plasma and intra-cellular membranes, remain electron-lucent. Among those selectively stained sites, our studies have been focussed on: (1) The dense synaptic material consisting of several presynaptic clumps, termed projections, an intrasynaptic dense line and a subsynaptic web from which fine fibrillar wisps extend into the surrounding ground substance; (2) Neurofilaments and neurotubules, the surface of which is bristled by numerous side-arms; (3) A microfilamentous network intertwines the neurotubules, the neurofilaments and the mitochondria in the dendrites and axon, and is also connected to the E-PTA dense undercoating delineating the inner aspect of the plasma membrane and to the fine wisps emanating from the subsynaptic web. A three-dimensional microfilamentous latticework is thus formed in the nerve cell processes; (4) Dense cytoplasmic inclusions, termed nematosomes, which are usually located in the ground substance of the perikaryon among or in the vicinity of clusters of ribosomes. Tiny microfilaments emanate from the peripheral strands of these bodies. The presence of basic residues in the chains of structural proteins of which consist the subsynaptic web and the nematosome is plausible, since the specificity of the E-PTA staining procedure for the detection of basic residues has previously been put forth. The occurrence of a three-dimensional microfilamentous network in the nerve cell processes led us to hypothesize that it plays a role in translocation of materials. It may provide the motive force for the axoplasmic transport, for instance, with the neurotubules, as well as, plausibly, with the neurofilaments, serving as attachment sites and guideways.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307481
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  • 32
    Digitale Medien
    Digitale Medien
    Ultrastructural studies of oogenesis in some european amphibians (1973)
    Springer
    Cell & tissue research 143 (1973), S. 387-407 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Oogenesis ; Urodela ; Yolk-formation ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Oogenesis was studied in adult Triturus vulgaris (Urodela) with the electron microscope. The oocytes investigated ranged between 50 μm and 1600 μm in diameter. Two types of yolk platelet formation were found. Since both types involve the incorporation of high numbers of pinocytotic vesicles they are believed to be of an extraoocytic origin. On the basis of the order of their appearance they were named primary and secondary yolk. Five different types of vesicles were found, which participate in a variety of activities, such as yolk formation and the formation of the Golgi apparatus. They originate from four different sources, namely the nuclear membrane, the cytoplasm in connection with ribosome-like particles, the Golgi apparatus and the plasma membrane through pinocytosis. The results obtained were discussed especially with respect to differences found between the anura and the urodela, such as the presence or absence of cortical granules or equivalent structures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307423
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  • 33
    Digitale Medien
    Digitale Medien
    Electron microscopic study on the larval and adult corpus allatum of Oncopeltus fasciatus dallas (insecta, heteroptera) (1973)
    Springer
    Cell & tissue research 145 (1973), S. 447-458 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Corpus allatum ; Oncopeltus fasciatus ; Larvae ; Imagines ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. The ultrastructure of the corpora allata of last larval instars and adults of Oncopeltus was studied. The unpaired gland undergoes submicroscopic alterations and shows signs of degradation in old animals. The organ is partly covered and penetrated by corpus cardiacum tissue. Axons with different types of neurosecretory granules form synaptoid contacts with the corpus allatum cells. 2. “Dark” and “light” gland cells can be differentiated on account of the degree of electron density. The former predominate during the last larval stage and in the young imago, the latter in mature males and females. It is highly probable that the “light” cells are the active (i.e. hormone producing) ones and the “dark” cells the inactive ones. 3. The active cells are characterized by rough endoplasmatic reticulum (often in whorls), small amounts of smooth endoplasmatic reticulum and many multivesicular bodies. Abundant free ribosomes, a not particularly well developed Golgi apparatus, dense bodies, and cytolysomes are present in active and inactive cells. 4. The nuclei contain one to four prominent and variously shaped nucleoli, which show differences between adult males and females with respect to their location in the nucleus. 5. The corpus allatum cells of Oncopeltus are obviously engaged in extensive protein synthesis. Tangible structural indications for the manufacture of juvenile hormone were not observed. Possible sites of hormone release are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306717
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  • 34
    Digitale Medien
    Digitale Medien
    Electron microscopic study of the substantia nigra and the strio-nigral projection in the rat (1973)
    Springer
    Cell & tissue research 146 (1973), S. 207-221 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Substantia nigra ; Rat ; Six bouton types ; Strio-nigral projection ; Bouton degeneration ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The normal ultrastructure of rat substantia nigra was investigated. Special attention was paid to the different types of boutons, and the mode of termination of the striatonigral connection was examined. Two different types of nigra neurons with deep nuclear membrane indentations were observed. The synaptic organization of rat substantia nigra is very complex. Six types of boutons, with many characteristics, could be differentiated: pleomorphicvesicle boutons (40%), elongated-vesicle boutons (10%), small-round-vesicle boutons (10%), large-round-vesicle boutons (20%), “clear-terminal” (15%) and dense-core-vesicle boutons (about 5%). Vesicle-containing dendrites were observed entering dendro-dendritic synapses. One to four days after large unilateral striatal lesions were made, a great number of degenerating boutons were seen in the ipsilateral substantia nigra, while the contra-lateral substantia nigra was entirely free of degeneration. The newly defined pleomorphic-vesicle boutons were found almost exclusively in the process of degeneration. The neuronal origin of the other bouton types is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307347
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  • 35
    Digitale Medien
    Digitale Medien
    Fine structure of capillaries in the pecten oculi of the sparrow, Passer domesticus (1973)
    Springer
    Cell & tissue research 146 (1973), S. 281-292 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Eye ; Bird ; Pecten oculi ; Capillaries ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The pecten oculi of the sparrow consists of capillaries, pigment cells and a superficial membrane. Because of the loose structure of the first two components broad intercellular spaces occur in the pecten. The capillary wall consists of endothelial cells and a perivascular membrane. The bodies of the endothelial cells are flattened, while the plasmalemma of both their surfaces (basal and luminal) is strongly folded and forms numerous microfolds with an average thickness of 700 Å. The height of the inner microfolds is 1.4–1.8 μm, the outer microfolds measure 1.3–1.6 μm. They lie densely packed side by side and are separated by recesses of the capillary lumen ca. 500 Å wide. Due to this the surface of the endothelial cell is increased by approximately 20-fold. The adjoining endothelial cells abut or overlap with margins, and are joined by the zonulae adherentes. Pigment cells form numerous processes and microvilli. Some rest on the capillary walls, while others penetrate the superficial membrane of the pecten or fill the intercellular spaces.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307352
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  • 36
    Digitale Medien
    Digitale Medien
    Axon retraction following guanethidine treatment (1973)
    Springer
    Cell & tissue research 146 (1973), S. 439-451 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Sympathetic neurons ; Axon retraction ; Guanethidine ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Vasa deferentia of rats chronically treated with high doses of guanethidine sulphate (30 or 60 mg/Kg/day i.p.) were examined using electron microscopic, fluorescence histochemical and pharmacological techniques. Counts of the axon population in segments of the proximal (urethral) end of the vas deferens showed a reduction to approximately 55% and 35% in the number of axon profiles after treatment for one week with the two dose levels respectively. In the same period only a few cell bodies in the hypogastric ganglion (from which most of the adrenergic innervation of the vas deferens arises) reached the stage of terminal degeneration. Although many axons showed some abnormalities, the number of axons observed in terminal stages of degeneration in treated tissue did not exceed, at any stage examined, the very small numbers observed in control tissue. Organ bath studies showed that the contractile response to transmural stimulation was lost fastest at the distal (epididymal) end of the treated vas deferens. These results have led to the conclusion that, in contrast to the degeneration of adrenergic axons produced by surgery or 6-hydroxydopamine, the sympathectomy produced by guanethidinein vivo involves theretraction of adrenergic axons prior to complete degeneration of the cell bodies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02347174
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  • 37
    Digitale Medien
    Digitale Medien
    Ultrastructure of nerve terminals and muscle fibers in denervated crayfish muscle (1973)
    Springer
    Cell & tissue research 146 (1973), S. 155-165 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Muscle ; Crayfish ; Synapse ; Degeneration ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Neuromuscular junctions, muscle fibers, and intramuscular nerve branches in crayfish opener muscles denervated for periods up to 368 days were examined with the electron microscope. The majority of the denervated muscles responded to stimulation of the isolated distal part of the motor axon with electrical activity and contractions. The neuromuscular junctions and muscle fibers appeared normal in such preparations: synapses and synaptic vesicles were present in the nerve terminals, and the organization of filaments and tubules in the muscle fibers was not distinguishable from that in normal muscles. In some preparations denervated for a long time, and in others denervated by tying the motor axon close to the muscle, the motor axons showed physiological and morphological evidence of degeneration. Synapses, when present in such preparations, showed few synaptic vesicles, which were often clumped. Muscle fibers showed signs of degeneration. These observations suggest that isolated distal motor axon segments can remain alive for at least a year, retaining normal structure. As long as the motor axon is viable, the muscle remains normal in appearance, but if the axon degenerates, the muscle becomes abnormal. A trophic interdependence between nerve and muscle is probably involved.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00307344
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  • 38
    Digitale Medien
    Digitale Medien
    Thermodynamic considerations in the formation of ergot alkaloids (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 207-211 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150116
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  • 39
    Digitale Medien
    Digitale Medien
    The influence of environmental conditions on the macromolecular composition of Candida utilis (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 239-255 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Glucose-limited chemostat cultures of Candida utilis were cultivated at various pH levels (3.0-7.5), temperatures (15-37.5°C), dilution rates (0.06-0.42 hr-1), and with different nitrogen sources (NH4+ and NO3-). The ratio of total nucleic acid to protein increased with increase in dilution rate at constant temperature and decreased with increase in temperature at constant dilution rate. The pattern of these variations is consistent with the hypothesis that the nucleic acid to protein ratio is a function of the ratio of the actual dilution rate to the critical dilution rate corresponding to each one of the cultivation temperatures. This ratio is called “reduced dilution rate.” A basis is proposed on which various microorganisms may be compared with respect to the ratios of cell protein to nucleic acid, RNA, ribosomal RNA, and polysomes.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150203
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  • 40
    Digitale Medien
    Digitale Medien
    Immobilization of whole cells in a membraneous form (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 565-569 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150312
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  • 41
    Digitale Medien
    Digitale Medien
    Effect of pressure on the hydrolysis of sucrose by invertase immobilized on collagen (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 583-588 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150315
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  • 42
    Digitale Medien
    Digitale Medien
    Masthead (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973) 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150401
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  • 43
    Digitale Medien
    Digitale Medien
    An extreme pressure pump for continuous cell disintegration (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 693-705 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The use of an air operated extreme pressure hydraulic pump for continuous cell disintegration is described, together with figures obtained for soluble protein released from suspensions of commercially obtained baker's yeast (Saccharomyces cerevisiae).
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150405
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  • 44
    Digitale Medien
    Digitale Medien
    Mass transfer and biochemical reaction with semipermeable microcapsules (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 467-481 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Enzymes can be encapsulated within a semipermeable membrane which allows reactants to enter and the products to diffuse out. The mass transport from the external fluid to the membrane and the combined mass transport and biochemical reaction from the membrane inwards can be modeled with recognized formulations; measurements of the overall reaction rate lead then to estimates of the permeability of the membrane itself.With capsules enclosing catalase, the permeability of collodion membranes to H2O2 is found to be large (〈2 × 10-2cm/sec) in comparison to rates in the other two diffusion zones. For this first-order reaction system, an analytical solution to the transient case of the well-stirred finite bath is found using the Laplace transform. With capsules enclosing urease, the nonlinear Michaelis-Menten kinetics apply to the enzymatic step. The steady-state operation of a column packed with urease microcapsules is analyzed with the aid of numerical computation and the membrane permeability for urea is found to be 10-3cm/sec.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150304
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  • 45
    Digitale Medien
    Digitale Medien
    Experimental and mathematical modeling studies of protozoan predation on bacteria (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 707-728 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The predation of bacteria by protozoan in both continuous and batch cultures was studied using experimental and modeling techniques. The predator organism was the ciliate, Tetrahymena pyriformis. The bacterium, Aerobacter aerogenes, served as the prey. Several batch growth responses were observed each initiated at a different nutrient level. Continuous cultures were conducted over a range of dilution rates. The models studied were partially successful in simulating the empirical data. Deviations between the model and the actual population behavior are discussed and possible explanations for the differences proposed.
    Zusätzliches Material: 18 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150406
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  • 46
    Digitale Medien
    Digitale Medien
    Protective support for fermentor electrodes and accessories (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 817-818 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150414
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  • 47
    Digitale Medien
    Digitale Medien
    Spectrophotometric determination of gramicidin and tyrocidine in fermentation broths (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 821-825 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 6 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150416
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  • 48
    Digitale Medien
    Digitale Medien
    The kinetics of yeast growth on pure hydrocarbons (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 861-877 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The kinetics of C. tropicalis growth were investigated with pure n-hexadecane as dispersed phase substrate. Two distinct growth phases were found: In the first phase, exponential growth was independent of stirrer speed. The onset of the second phase, one of linear growth, was determined by stirrer speed. By the use of two different fermenter types, it was shown that the drop size of the dispersed phase was not primarily responsible for the observed kinetics. It was considered that the formation of biological flocs determined the observed growth pattern. This was substantiated by the results of continuous cultures in the different fermenter types, with various substrate concentrations.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150504
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  • 49
    Digitale Medien
    Digitale Medien
    Oxygen absorption in stirred tanks: A correlation for ionic strength effects (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 755-782 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A new correlation is given for the prediction of the volumetric coefficient for mass transfer (KLa) in stirred tanks from dispersed gas bubbles to basal salt solutions of ionic strengths representative of fermentation media. The correlation includes the effects of both the operating parameters (agitation power per unit volume and gas superficial velocity) and the physicochemical properties of the system: interfacial tension, viscosity, density, diffusion, coefficient and, in particular, ionic strength. The effect of the latter was found to be most significant in the Newtonian systems of water-like viscosity investigated; no previous correlations have included the effect of ionic strength. KLa values were determined by using a dissolved oxygen probe to monitor the steady-state oxygen tension in continuous flow experiments, and/or the rate of change of oxygen tension in unsteady-state semibatch experiments. In the latter cases, results were computed by a nonlinear, least squares computer program which fitted the experimental data to a model of probe transient response characteristics. The general applicability of the model and the computational procedure was verified by comparing the results to those obtained with the same electrolyte solution in the steady-state mode. The experiments were run over a wide range of agitation power inputs, including those typical of both soluble- and insoluble-substrate fermentations. The correlation appears to be valid for both oxygen mass transfer with and without homogeneous chemical reaction in the liquid phase; in the former case, for example, sulfite oxidation, knowledge of the chemical reaction enhancement factor is required. In addition to predicting oxygen transfer capabilities, the correlation may be used for other sparingly soluble gases of interest in fermentation systems, such as methane, hydrogen, and carbon dioxide.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150409
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  • 50
    Digitale Medien
    Digitale Medien
    Preparation and properties of an immobilized Barley β-amylase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 783-794 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Barely β-amylase (α-1,4-glucan maltohydrolase, EC 3.2.1.2) has been immobilized by covalent fixation to amino derivatives of epichlorohydrin crosslinked Sepharose mediated by cyclohexyl isocyanide and acetaldehyde. The enzyme conjugates contain up to 35% of the total activity of the β-amylase added to the coupling mixture. The profiles of activity versus pH and ionic strength are essentially the same for free and immobilized β-amylase, whereas the resistance to inactivation during storage and use is considerably enhanced by immobilization. Columns with immobilized β-amylase have been used for continuous degradation of starch. At 45°C, half of the initial activity remains after seven weeks, and the corresponding figure at 23°C is 85 percent.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150410
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  • 51
    Digitale Medien
    Digitale Medien
    Accumulation of 5′ guanine nucleotides by mutants of Brevibacterium ammoniagenesThis is Part XLII of the series of reports entitled “Production of Nucleic Acid- Related Substances by Fermentative Processes”. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 795-803 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: 5′Xanthylic acid was efficiently converted to 5′guanine nucleotides (5′GMP, 5′GDP, and 5′GTP) without being degraded to guanine via 5′GMP by decoyinine resistant mutants of strain KY 13315 which had been isolated from Brevibacterium ammoniagenes and was practically devoid of 5′nucleotide degrading activity. The concentration of phosphate in the medium showed a profound effect on the ratio of the accumulated 5′guanine nucleotides, making it possible to direct the fermentation towards 5′GMP or 5′GTP. A direct accumulation of 5′guanine nucleotides from carbohydrate was possible by mixed cultivation of a 5′XMP accumulating strain and a 5′XMP converting mutant. A maximum concentration of 9.67 mg of 5′guanine nucleotides per ml was obtained directly from glucose in such a mixed culture.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150411
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  • 52
    Digitale Medien
    Digitale Medien
    Preparation of immobilized enzymes by electron-beam irradiation (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 827-829 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150417
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  • 53
    Digitale Medien
    Digitale Medien
    Effects of polymer additives on fermentation parameters in a culture of A. niger (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 845-859 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Of 24 different polymer and surfactant materials examined, a carboxypolymethylene (“Carbopol”) was found to cause enhancement of respiration rates in an Aspergillus niger culture by as much as 200%. Enhancement of other fermentation parameters, such as cellular growth and amylase production, was also observed.The enhancement effects of Carbopol were examined with clusters of spores and mold pellets. In the first case, it appears that the ionized carboxyl groups of Carbopol induced electrostatic repulsion among the spores thus initiating pulp growth with increased interfacial area of contact between the mold and the nutrient medium. In the second case, the Carbopol additive formed a thin film attached to the surface of the pellets which seemed to be responsible for an increased rate of potassium transport and, hence, fermentation yields. Additive utilization as substrate and physiological changes in the culture were not observed in these cases.It was also found that the probability of pellet formation, the size of pellets formed, and the number of spores per pellet can be correlated to the energy input to the fermentation system.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150503
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  • 54
    Digitale Medien
    Digitale Medien
    Effectiveness factor calculations for immobilized enzyme catalysts (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 879-888 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The steady state, nonlinear diffusion equations which describe reactions in constrained enzyme solutions are of great interest in many biological and engineering applications. As in other types of nonlinear differential equations, exact analytical solutions do not exist except in some simplified cases. In this paper, a general procedure is presented for solving numerically for the substrate concentration profile and effectiveness factor utilizing the transformation method suggested by Na and Na. Design correlations for enzyme solutions constrained within spherical membranes are included. The use of a unique definition of the Thiele Modulus in these charts permits the clear illustration of the effects of substrate concentration and external mass transfer resistances on the overall effectiveness factor for the catalyst particle.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150505
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  • 55
    Digitale Medien
    Digitale Medien
    Masthead (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973) 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150601
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  • 56
    Digitale Medien
    Digitale Medien
    Isolation and characterization of constituents in hemolymph from healthy and diseased japanese beetle larvae (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1023-1037 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Studies are reviewed on the composition of hemolymph from Japanese beetle larvae, Popillia japonica. This research was conducted to determine the chemical environment required for sporulation of the milky disease organism, Bacillus popilliae. Amino acids, proteins, organic acids, lipids, carbohydrates, and oxygen content were determined in hemolymph from healthy and diseased larvae. Oxygen content of hemolymph was measured by microelectrodes implanted in the hemocoel of living larvae. Vegetative growth of the pathogen reduces the dissolved oxygen; however, as sporulation occurs, oxygen concentration approaches normal values. Trehalose, the major hemolymph sugar, is reduced by ca. 50% during the course of milky disease. Neutral lipids, phospholipids, and hydrocarbons decrease markedly with infection. Both branched-chain and normal alkanes occur in hemolymph. Milky disease causes an increase in concentration of pyruvic, malic, glycolic, tartaric, and glyoxylic acids. The major hemolymph protein, a lipoglycoprotein, has a mol. wt. of ca. 500,000. Reduced concentration of this protein is accompanied by the appearance of a smaller protein. Amino acids that increase significantly as a result of infection are: Glutamic acid, aspartic acid, β-alanine, phenylalanine, threonine, lysine, and serine. Hemolymph contains few peptides of low molecular weight.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150603
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  • 57
    Digitale Medien
    Digitale Medien
    Fungal cultures and culture mediums for the production of cellulase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1123-1129 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Cellulase production by strains of Myrothecium verrucaria, Stachybotrys atra and Trichoderma viride was examined. Myrothecium verrucaria was found to give the greatest yields. A variety of media were examined as potential substrates for the industrial production of cellulase. The salts content of the medium was varied and was found to affect cellulase production. Glucose, carboxymethylcellulose (CMC), filter paper and three industrial wastes were examined as possible cellulase inducers. Filter paper was found to be the most effective, followed by sugar cane bagasse and CMC.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150610
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  • 58
    Digitale Medien
    Digitale Medien
    Masthead (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973) 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150101
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  • 59
    Digitale Medien
    Digitale Medien
    Film and pore diffusion studies with immobilized glucose oxidase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 143-161 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Quantitative studies are reported of external film and internal pore diffusion effects for glucose oxidase immobilized on porous glass in a continuous, tubular, packed bed reactor. The McCune and Wilhelm model for external film diffusion is shown to describe these data over a particle Reynolds number range from 0.2 to 25. The Thiele analysis provides a good description of internal pore diffusion resistances. It appears that immobilized enzymes free of internal diffusional restrictions generally require the use of supports with pore sizes larger than those currently available in porous glass.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150111
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  • 60
    Digitale Medien
    Digitale Medien
    A method for characterizing the rheological properties of viscous fermentation broths (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 201-206 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150115
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  • 61
    Digitale Medien
    Digitale Medien
    Studies on immobilized papain (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 455-466 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Papain was covalently coupled to ZrO2-coated porous glass by several different methods. These derivatives were characterized and their operational half-lives determined using casein substrate. Papain covalently coupled to the porous glass, previously converted to a carboxylic acid derivative, through amide linkage gave a 35 day operational half-life.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150303
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  • 62
    Digitale Medien
    Digitale Medien
    An apparatus to measure the rate of oxygen evolution while maintaining pO2 constant during photosynthetic growth in closed culture vessels capable of operation at increased hydrostatic pressures (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 505-518 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A double polarographic device is described which permits regulation of dissolved oxygen concentration at any preset pO2 in suspensions or cultures of photosynthetic algae. It also simultaneously permits measurements of the rate of oxygen evolution during photosynthesis. The apparatus is designed to operate in closed vessels in the absence of a gas phase, and may be used at increased pressures tested up to 500 atmospheres. Regulation of oxygen levels was maintained constant at various preset concentrations equivalent to atmospheric pO2 values ranging between 0.02 and 0.21 at 25°C.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150307
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  • 63
    Digitale Medien
    Digitale Medien
    Phospholipase-C from Bacillus cereus: Production, purification, and properties (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 551-560 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A substrain of Bacillus cereus 569/H produced under controlled fermentation conditions in a pilot plant fermentor phospholipase-C. A partially purified preparation showed good storage stability as a lyophylized powder and in frozen solutions. The preparation contained very small amounts of phosphomonoesterase and proteolytic activities and essentially no ribonuclease activity. The level of hemolytic activity of the preparation was much lower than that of a commercial preparation of phospholipase-C from Clostridium. Treatment of sarcoplasmic reticulum membrane with phospholipase-C from B. cereus and from Clostridium showed that the B. cereus enzyme caused hydrolysis of 96% of the membrane phospholipids whereas the enzyme from Clostridium could hydrolyze only 80% of the phospholipids.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150310
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  • 64
    Digitale Medien
    Digitale Medien
    Mixed culture biooxidation of phenol. I. Determination of kinetic parameters (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 889-896 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A mixed culture derived from soil and activated sludge organisms was used to degrade phenol which was inhibitory to microorganisms at higher concentrations. The purpose of the experiments was to determine the kinetic parameters governing growth of the organisms by measuring growth rates in batch culture. To maintain a constant inoculum for the experiments inoculum was taken from a continuously operating continuous culture. Two populations were studied corresponding to two separate residence times in the continuous culture apparatus. One contained predominantly filamentous organisms, the other nonfilamentous. Five kinetic models were applied to the data and the best kinetic parameters for each model were determined by nonlinear least squares techniques. The models were then evaluated for best relative fit to the data. No significant differences were found between the models on the basis of fit and so a choice was made on the grounds of simplicity. A model proposed by Haldane was chosen as the best. No function however gave a satisfactory fit at the highest growth rates obtained. This experimental maximum in the plot of growth rate against substrate concentration was very sharp.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150506
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  • 65
    Digitale Medien
    Digitale Medien
    Mixed culture biooxidation of phenol. III. Existence of multiple steady states in continuous culture with wall growth (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 905-916 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: It is shown that two steady states exist in certain regions of operation of a 2-liter continuous stirred tank biological reactor. Transition was made from one steady state to another by applying shock loads of either phenol substrate which is inhibitory to the culture at high concentrations or by adding large additional amounts of concentrated organisms. The existence of the multiple steady states is ascribed to the existence of wall growth, and their position is determined by the amount of wall growth. Transient behavior of the system did not follow the predictions of the simple wall growth model but the culture appeared to undergo a lag period immediately after applying the shock load to the system. It is concluded that the stability of a continuous culture utilizing an inhibitory substrate is improved by increasing the degree of wall growth and decreasing the substrate feed concentration. It is also concluded that small scale experiments can usually not be interpreted correctly unless the effect of wall growth is taken into account.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150508
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  • 66
    Digitale Medien
    Digitale Medien
    Response of completely mixed systems to pH shock (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 933-949 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The response of aerobically growing heterogeneous microbial populations of sewage origin to step increases and decreases in pH were studied in both once-through and cell recycle systems. The pH range studied was 2.7 to 8.0. All studies were conducted at a dilution rate of 0.125 hr-1, and all shocks were administered from a base or preshock pH level of 6.4 to 6.7. In each experiment, the preshock or initial “steady state” was assessed, the pH of the feed changed, and the resulting transient behavior of the system examined until attainment of the new or final “steady state” was approached. The major objectives of the work were to characterize the nature of the response with respect to biomass and effluent substrate concentrations, types of microbial populations present and chemical composition of the biomass, and to obtain guidelines as to allowable change in pH in waste streams. It was found in once-through systems that substrate removal efficiency recovered from pH levels as low as 3.0 after rather long periods of transient leakage of substrate. Cell recycle attenuated the severity of substrate leakage. In all cases of severe acid shock, the microbial population changed from predominantly bacterial-protozoan to one consisting predominantly of filamentous fungi. Changes in chemical composition of the sludge (protein and carbohydrate content) were consistent with the population changes. Based upon the results, it can be conservatively estimated that changes in pH of no more than one unit from the neutral preshock range can be tolerated without possible disruption of biochemical efficiency of substrate removal.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150511
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  • 67
    Digitale Medien
    Digitale Medien
    Activity and specificity of covalently immobolized wheat germ agglutinin toward cell surfaces (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 981-992 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Wheat germ agglutinin protein, which is able to agglutinate tumor cells better than normal cells, was covalently bound to polyacrylamide gel beads. The specific binding activity of the protein was preserved on these beads and was expressed heterogeneously by the binding of mouse leukemia cells (L1210) to the protein coupled gels. The selective activity of the immobilized protein was maximal when the number of sites available to covalently couple the protein was lowest. The application of this observation to the general field of covalent immobilization of proteins and enzymes may be of considerable utility.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150515
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  • 68
    Digitale Medien
    Digitale Medien
    Collagen-enzyme complex membranes and their performance in biocatalytic modules (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 93-115 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Collagen was used as carrier for the immobilization of invertase, lysozyme, urease, glucose oxidase, penicillin amidase, and glucose isomerase. Immobilization was accomplished by either impregnation of a preswollen collagen membrane with enzyme solution or electrocodeposition of collagen and enzyme from a collagen dispersion containing dissolved enzyme. The collagen-enzyme complexes prepared are in membrane form.Membranous collagen-enzyme complexes were used to construct biocatalytic reactors such as the capillaric coil modular reactor. Such biocatalytic reactors were used in a recirculation system for the conversion of substrates. The biocatalytic reactors showed initial decreases of activity to stable limits which are maintained over a large number of reactor volume replacements. The stable limits correspond to approximately 35% of the initial activities for lysozyme and invertase, 25% for urease, 15% for glucose oxidase.The mechanism of complex formation between collagen and enzyme involves multiple salt linkages, hydrogen bonds, and van der Waals interactions. This protein-protein interaction which leads to stable complexes by both impregnation and electrocodeposition processes is unique among the enzyme immobilization methods currently available.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150108
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  • 69
    Digitale Medien
    Digitale Medien
    Kinetic analysis of diauxic growth and pectolytic enzyme formation in aspergilli (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 163-179 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Kinetic studies on the growth of Aspergillus strains as well as constitutive and inductive polygalacturonase formation have been made in bath fermentations, without pH control. Equations describing growth and product formation of the four-stage growth of microorganisms were applied for the first time to diauxic growth and enzyme formation of Aspergillus strains. Diauxic growth of the cultures has been found in both sucrose- and peetin-containing media. Enzyme concentration in the second transient phase, calculated by the use of new equations, proved to be negligible. In the exponential and declining phases, the calculated values of mycelial and enzyme concentrations were in good agreement with the values observed. Types of classification of the product formation of Luedeking and Piret refer to the second cycle of diauxie. The types of product formation described by Kono and Asai and Luedeking and Piret are mostly in good agreement with each other. The greatest difference has been found in the case of inductive endo-polygalacturonase formation, where the final enzyme formation could not be plotted because of the decrease (autolysis) in mycelial weight.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150112
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  • 70
    Digitale Medien
    Digitale Medien
    Lactase immobilization on phenolic resins (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 597-602 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150317
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  • 71
    Digitale Medien
    Digitale Medien
    Nonbiodegradable and other racalcitrant molecules (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 611-647 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150402
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  • 72
    Digitale Medien
    Digitale Medien
    Diffusion and reaction in a double enzyme supported catalyst (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 217-221 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150118
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  • 73
    Digitale Medien
    Digitale Medien
    Sampling procedures for non-newtonian fermentation broths (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 579-581 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150314
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  • 74
    Digitale Medien
    Digitale Medien
    Preparation of immobilized enzymes using poly(vinyl alcohol) (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 607-610 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150319
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  • 75
    Digitale Medien
    Digitale Medien
    Methionine control of cephalosporin C formation (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 743-754 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: DL-Norleucine, a nonsulfur analogue of methionine was found to markedly stimulate synthesis of cephalosporin C by Cephalosporium acremonium strain CW19 in three different chemically defined media. Methionine, but not norleucine, stimulated cephalosporin C biosynthesis in a crude medium. The lack of stimulation by norleucine in complex medium was shown to be due to lack of uptake of this amino acid by mycelia growing in such a medium. In defined media containing a suboptimal methionine concentration, norleucine stimulated antibiotic production up to the level reached by optimal methionine. At an optimal dose of methionine, norleucine elicited no further increase in cephalosporin C production, indicating that these two amino acids act by the same mechanism. The data strongly indicate that stimulation by methionine is not a function of its ability to donate sulfur for antibiotic formation. Methionine was found to neither repress nor inhibit cysteine metabolism.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150408
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  • 76
    Digitale Medien
    Digitale Medien
    A geometrical approach for differentation of an experimental function at a point: Applied to growth and product formation (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 805-810 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150412
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  • 77
    Digitale Medien
    Digitale Medien
    Rate of coagulation of single cell Protein concentrate (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 819-820 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150415
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  • 78
    Digitale Medien
    Digitale Medien
    Biopolymers in drug technology: The use of DNA in purifying Phleomycin (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1039-1044 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: It is sometimes easier and cheaper to extract a drug's target sites from cells than it is to purify, concentrate or manufacture the drug itself. This is especially true in the case of DNA and some of the exotic antibiotics that react with it. Phleomycin, an inhibitor of replication, was considered as a specific case in point. Biologically active components of this antibiotic mixture bind nondestructively to DNA, in vitro and in vivo, and thereafter may be processed by simple, economical methods usually reserved to macromolecules of much greater size.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150604
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  • 79
    Digitale Medien
    Digitale Medien
    Steady state multiplicity and stability of enzymatic reaction systems (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1131-1145 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Several techniques for investigating the multiplicity and stability of open isothermal enzymatic reactors are discussed and some of the pitfalls in previous thinking pointed out. The example which is used to illustrate these methods exhibits several interesting features. Among these is the existence of a stable oscillatory state which surrounds a unique steady state which is asymptotically stable to certain finite disturbances.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150611
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  • 80
    Digitale Medien
    Digitale Medien
    Equations of substrate-limited growth: The case for blackman kinetics (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1159-1177 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A simplified model of cell metabolism, consisting of a series of linked reversible enzymatic reactions dependent on the concentration of a single external substrate has been developed. The general mathematical solution for this system of reactions is presented. This general solution confirms the concept of a rate-limiting step, or “master reaction”, in biological systems as first proposed by Blackman. The maximum rate of such a process is determined by, and equal to, the maximum rate of the slowest forward reaction in the series.Of practical interest in modeling the growth rate of cells are three cases developed from the general model. The simplest special case results in the Monod equation when the maximum forward rate of one enzymatic reaction in the cell is much less than the maximum forward rate of any other enzymatic reactions.More realistic is the case where the maximum forward rates of more than one enzymatic reaction are slow. When two slow enzymatic reactions are separated from each other by any number of fast reactions that overall can be described by a large equilibrium constant, the Blackman form results: \documentclass{article}\pagestyle{empty}\begin{document}$$\mu = [S]/A, \rm{when} [S] 〈 A\mu_{\rm{max}}$$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$$\mu = \mu_{\rm{max}}, \rm{when} [S] \rm{〉} A\mu _{\rm{max}}$$\end{document}A third case is that in which two slow enzymatic steps are separated by an equilibrium constant that is not large. Unlike the Monod and Blackman forms, which contain only two arbitrary constants, this model contains three arbitrary constants: \documentclass{article}\pagestyle{empty}\begin{document}$$[S] = \mu A + \frac{{\mu B}} {{(\mu_{\rm{max}} - \mu)}}$$\end{document}The Monod and Blackman forms are special cases of this three constant form.In comparing equations with two arbitrary constants the Monod equation gave poorer fit of the data in most cases than the Blackman form. It is concluded that workers modeling the growth of microorganisms should give a t least as much consideration to the Blackman form as is given to the Monod equation.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150613
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  • 81
    Digitale Medien
    Digitale Medien
    Mannose-containing polysaccharides of yeasts (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1-12 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The known species of yeasts produce at lest 180 different polysaccharides having mannose as a major constituent. The type of mannan formed is characteristic of the yeast species, and can be used as an aid in identification and classification. The immunological characteristics of yeasts depend largely upon the nature of the mannans. Some of the yeast mannans can be produced in relatively high yields, and have been suggested as replacements for plant and bacterial gums as thickeners, dispersing agents, and similar applications. However, more significant uses, based on the finer differences in their chemical structures and the specific reactions they undergo, may result from a closer study of these polymers.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150102
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  • 82
    Digitale Medien
    Digitale Medien
    Thermal stability of glucose oxidase and its admixtures with synthetic polymers (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 917-925 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The thermal stability of glucose oxidase in solution was studied as a function of time and temperature between 37-60°C. As expected, the rate of thermal inactivation increased with temperature and at 60°C more than 80% of the enzyme's activity was lost after 0.5 hr incubation. Similar stability measurements on enzyme solutions containing water soluble synthetic polymers showed that several of the polymers significantly enhanced the thermal stability of glucose oxidase. Copolymers of vinyl acetate with either vinyl pyrrolidone or vinyl alcohol were found to be particularly effective. The molecular weight of the added polymers was found to be unimportant in the stabilization process but both polymer concentration and compositions were shown to be critical parameters.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150509
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  • 83
    Digitale Medien
    Digitale Medien
    Insolubilized amylases (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 951-962 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Carrier-bound immobilized α-amylases and glucoamylase have been obtained by photopolymerizing aqueous solutions containing acrylamide, a crosslinking monomer, an enzyme-reactive monomer, an oxygen scavenger, and amylase, and allowing the amylase to react with the entrapping enzyme-reactive gel matrix evolved. Partial starch hydrolyzates (28 DE corn starch syrup) have been continuously converted to 90-94% dextrose syrups in columns packed with immobilized amylases. The enzymatic heat stability of immobilized glucoamylase gels is discussed.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150512
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  • 84
    Digitale Medien
    Digitale Medien
    Lysis ofMicrococcus lysodeikticus by lysozyme covalently immobilized on cellulose and polyacrylamide (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 993-1006 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Lysozyme immobilized on polyacrylamide beads or cellulose fibers is found to retain activity for hydrolysis of the cell walls of Micrococcus lysodeikticus. The immobilization on cellulose is somewhat reversible; the polyacrylamide immobilized lysozyme does not release any enzyme upon washing as evidenced by UV and lytic activity tests. The specific catalytic activity of the lysozyme-polyacrylamide system is found to decline as the density of derivatized surface groups is increased; a model of protein deactivation due to excess surface coupling is presented as a possible rationale for such specific activity variations.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150516
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  • 85
    Digitale Medien
    Digitale Medien
    Chemical and autoflocculation of microorganisms in biological wastewater treatment (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1045-1073 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Experimental evidence is presented which indicates that both chemical and autoflocculation of microorganisms occur by the same mechanism. Basically, long chain polymeric species attach themselves between the microbial particles and agglomerate them into flocculant particles of sufficient magnitude to subside from suspension under quiescent conditions. Properties of the polymers which are produced during autoflocculation are investigated and these polymers are shown to be capable of causing the agglutination of inorganic colloids such as alumina. It is hypothesized that these biologically generated flocculating polymers could belong to a class of compounds known as transport enzymes. The experimental data qualitatively agrees with this hypothesis.
    Zusätzliches Material: 13 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150605
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  • 86
    Digitale Medien
    Digitale Medien
    Multiple immobilized enzyme reactors: Determination of pyruvate and phosphoenolpyruvate concentrations using immobilized lactate dehydrogenase and pyruvate kinase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1089-1100 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Lactate dehydrogenase (LDH) and pyruvate kinase (PK), immobilized on solid glass beads by diazotization, were used in packed bed reactors to analyze for both pyruvate (PYR) and phosphoenolpyruvate (PEP) through the disappearance of β-nicotinamide adenine dinucleotide (NADH) monitored spectrophotometrically at 340 nm. Packed bed reactors containing PK and/or LDH were also capable of monitoring continuously varying concentrations of adenosine-5′-diphosphate (ADP), PEP, and PYR. The immobilized enzymes (∼40 μg/g glass) retained about 4% of the activity of the soluble enzymes. Preparations of immobilized LDH and PK exhibited enhanced stability when maintained in the presence of β-mercaptoethanol and NADH or EDTA, respectively, and were shown to regain 75% of the original activity after four months storage at 4°C.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150608
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  • 87
    Digitale Medien
    Digitale Medien
    Acid-Base equilibrium in aerobic fermentations: Influence of unutilizable acids and bases on the acetic acid concentration in culture liquidThis paper was presented at the Annual Meeting of the Agricultural Chemical Society of Japan at Sendai, April 2, 1972. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1147-1158 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: An investigation was made on the factors influencing the acetic acid concentration in the culture liquid of the aerobic fermentations where acetie acid was used as a carbon source. The acetic acid concentration in the culture liquid changed in proportion to the amount of unutilizable acid or base supplied. This was explained by the principle of conservation of electroneutrality.Another factor affecting the acetic acid concentration in the culture liquid was bicarbonate ions which were formed by the dissolution and dissociation of carbon dioxide in the gas phase of the fermentor. The increment in bicarbonate ion concentration was equal to the decrement in the acetie acid concentration in the culture liquid.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150612
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  • 88
    Digitale Medien
    Digitale Medien
    Microprobe measurements of oxygen concentrations in mycelial pelletsPresented at 164th American Chemical Society National Meeting New York, New York, August, 1972. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1193-1197 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150616
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  • 89
    Digitale Medien
    Digitale Medien
    Glutamic acid production with gel-entrapped Corynebacterium glutamicum (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 973-979 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A glutamic acid producing microorganism (Corynebacterium glutamicum) is entrapped in a polyacrylamide gel. These immobilized microorganisms were used to produce glutamic acid in successive batches of fresh medium. Free microorganisms similarly used produced much less glutamic acid under similar conditions.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150514
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  • 90
    Digitale Medien
    Digitale Medien
    Calorific contents of microorganisms (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1007-1010 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150517
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  • 91
    Digitale Medien
    Digitale Medien
    Binding of papain to dialdehyde starch (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1189-1192 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150615
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  • 92
    Digitale Medien
    Digitale Medien
    Binding of end product in the fermentation of nucleotides (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 85-91 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Flavor enhancing nucleotides may be produced by streptomycetes. Mutants of streptomyces 772 were found to produce, under ordinary fermentation conditions, considerable amounts of 5′-IMP and 5′-XMP, but only traces of 5′-GMP. This was probably due to the feedback inhibition of the end product GMP. It was shown that through suitable fermentation techniques it was possible to overcome this internal control mechanism, leading to increased yields of 5′-GMP.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150107
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  • 93
    Digitale Medien
    Digitale Medien
    Preparation of immobilized invertase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 403-412 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Immobilized invertase was prepared by ionically binding the enzyme to diethylaminoacetyl cellulose (DEAA-cellulose). DEAA-cellulose-invertase complex was quite stable to electrolyte in the range of pH 5-7. Bound invertase was less active than the native enzyme, and approximately 55-70% of the enzyme activity was lost on binding. The complex was stable for 9 days' continuous inversion in a column system at 30°C, but was rather unstable at 40°C. Heat stability and the effect of temperature on the reaction rate of the complex were almost identical with those of the native enzyme.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150214
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  • 94
    Digitale Medien
    Digitale Medien
    Analysis of membrane reactor performance for hydrolysis of starch by glucoamylase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 441-445 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150217
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  • 95
    Digitale Medien
    Digitale Medien
    The “azotopure” process for treating nitrogen-deficient aqueous wastesPresented at 164th National Meeting of American Chemical Society, New York, N. Y., August 28-31, 1972. (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 413-418 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Many chemical and food processing wastes are deficient in nitrogen, and must therefore be supplemented with domestic sewage or ammonia to dispose of them by conventional biological treatment. A more economical treatment, especially of strong wastes, is possible by maintaining a semipure culture of nitrogen-fixing bacteria in a stirred aerated tank. When operated as a chemostat with 4 to 6 hr detention time, removal of 85% of the COD is possible in a single step without the need for clarifiers or digesters. A clarified effluent could also be produced by flotation or sedimentation of the flocculated bacteria. In that case there would be 99% removal of COD and a reduction in the amount of sludge by two-thirds over the conventional activated sludge process.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150215
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  • 96
    Digitale Medien
    Digitale Medien
    Cell growth and extracellular enzyme synthesis in fermentations (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 419-439 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The synthesis of extracellular enzymes by microorganisms frequently occurs under genetic control. A simple two-parameter model is developed describing the degree of repression or induction in fermentation media.The case of substrate utilization by an extracellular enzyme was analyzed for a vegetable oil-lipase-yeast system. It is shown that fatty acids released by the lipase may accumulate in the early stage of growth and exert an influence on the limiting after which relatively little repression or induction takes place.Expressions are also derived for growth and extracellular enzyme synthesis in single-and multistage continuous cultures. When the cells grow on a directly available soluble substrate, the specific enzyme synthesis is maximal at low dilution rates in the case of repression and at high dilution rates in the case of induction. If the substrate is not directly available, a single continuous stirred tank reactor stage may not be sufficient for efficient substrate utilization; for fermentation processes where an insoluble has to be broken down before the cells can assimilate it, a plug flow type fermentor rather than a mixed chemostat may prove more satisfactory.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150216
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  • 97
    Digitale Medien
    Digitale Medien
    Masthead (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973) 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150301
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  • 98
    Digitale Medien
    Digitale Medien
    Production of microbial protein from waste cellulose by Thermomonospora fusca, a thermophilic actinomycete (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 833-843 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The growth characteristics of Thermomonospora fusca, a cellulolytic thermophilic actinomycete, are described in terms of growth on pulping fines, a cellulosic waste of the paper industry. A fermentation was developed which substantially degrades this waste, with the residual product of growth containing about 30% microbial protein. This protein, as shown by a preliminary feeding study with baby chicks and by amino acid analyses, appears to be of good nutritional quality and contains no strongly toxic materials. The extracellular cellulolytic enzymes present in the spent broth are discussed in relation to their potential recovery as a by-product of the fermentation, as is also the possible use of the fermentation as a waste disposal system.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150502
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  • 99
    Digitale Medien
    Digitale Medien
    Water-soluble enzyme-polymer grafts: Thermal stabilization of glucose oxidase (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1011-1016 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150518
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  • 100
    Digitale Medien
    Digitale Medien
    A modified procedure for the large scale preparation of tRNA from E. coli (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 1081-1088 
    Details
    ISSN: 0006-3592
    Schlagwort(e): Chemistry ; Biochemistry and Biotechnology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: A procedure for the preparation of about 50 g batches of tRNA from 25 kg E. coli W is described. The method involves phenolic extraction of the cells, batch absorption of the tRNA on DEAE-cellulose, washing the DEAE-cellulose and packing it into a column, elution of the tRNA from the column and precipitation of the tRNA with ethanol. The method is less time and labor consuming than the methods described in the literature and can be carried out with relatively simple equipment.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bit.260150607
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