Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1975-1979  (362)
  • 1970-1974
  • 1975  (362)
  • Biochemistry and Biotechnology  (167)
  • Electron microscopy  (111)
  • Engineering General  (84)
Material
Years
  • 1975-1979  (362)
  • 1970-1974
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 368 (1975), S. 99-108 
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Calcium ; Parathyroid glands ; Chief cells ; Oxyphil cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using the potassium pyroantimonate technique for ultrastructural localization of cations and X-ray elemental analysis with both energy dispersive and wave-length dispersive systems, calcium-containing precipitates were found in normal, hyperplastic and adenomatous human parathyroid glands. Differences were observed between oxyphil cells, and suppressed, stimulated and active chief cells in the content and localization of intracellular precipitation. The oxyphil cells and suppressed chief cells possessed precipitates mainly in nuclei and medium-sized and large mitochondria, whereas the stimulated chief cells possessed precipitates in normal-appearing and morphologically altered mitochondria, and in smooth-surfaced vacuoles and cytosol. The active chief cells usually showed a rather sparse precipitation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 369 (1975), S. 19-27 
    ISSN: 1432-2307
    Keywords: Alpha-1-antitrypsin deficiency ; Liver ; Electron microscopy ; Endoplasmic reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fourteen liver biopsies from twelve young patients with liver diseases associated with homozygous, PiZZ phenotype, alpha-1-antitrypsin deficiency in their sera were examined by electron microscopy. In all these biopsies characteristic homogeneous material was found in some hepatocytes and corresponded, when observed on adjacent semithin sections by light microscopy, to the deposit stained by periodic acid Schiff reaction. The accumulation in perinuclear spaces resulted in intranuclear invaginations, but the major deposit was located in lumens of the endoplasmic reticulum. The limiting membranes were rough and smooth but the extent of the latter was so large that only this type of reticulum seemed peculiarly involved in the accumulating process. On the contrary, Golgi complexes did not seen obligatorily involved by this process because, when observed, they appeared almost normal even in heavily overloaded liver cells. At least for the PiZZ phenotype, the abnormal substance would be an asialo form of normal alpha-1-antitrypsin. Thus the subject of this study is the morphologic translation of an impairment in the synthesis of a glycoprotein. In the light of data concerning the synthesis of such proteins our findings lead us to suggest: The ultrastructural patterns observed in alpha-1-antitrypsin deficiency cannot give the expected morphologic evidence of the biochemical data which locate the first binding steps of monosaccharide residues in the rough endoplasmic reticulum. The absence of sialic acid could not result from an enzymatic defect primarily located in Golgi complexes but could be secondary to an impairment in the binding of one monosaccharide residue which improves subsequent fixation of sialic acid, in the smooth endoplasmic reticulum. Finally it seems necessary to emphasize that the relationship between the abnormal substance and various important non specific lesions is largely unknown and that we don't know the significance of polymorphous dense bodies observed in ductular cells during the cholestatic period.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2307
    Keywords: Tumors of the skin ; Histogenesis ; Classification ; Labyrinth nuclei ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über den Feinbau folgender Hauttumoren berichtet: Dermatofibrom (7 Fälle), Histiozytom (4 Fälle), Dermatofibrosarcoma protuberans (1 Fall) und Fibroxanthom (1 Fall). Aufgrund ihrer unterschiedlichen ultrastrukturellen Merkmale ist eine zweifache Unterteilung dieser Hauttumoren möglich: In eine Tumorgruppe, umfassend das Dermatofibrom, Dermatofibrosarcoma protuberans und Fibroxanthom, bei der die Faserbildung im Vordergrund steht und für deren Histogenese Fibroblasten angenommen werden können. Diese Tumortypen unterscheiden sich vom Histiozytom, dessen Zellcharakter vor allem durch die stark ausgeprägte Phagozytose- und Speichertätigkeit (Fett und Hämosiderin) bestimmt wird und für welches eine histogenetische Ableitung von Histiozyten wahrscheinlich ist. Die Zellkerne des Dermatofibromes und des Histiozytomes weisen einen einfachen Oberflächenverlauf auf, die des Dermatofibrosarcoma protuberans und Fibroxanthomes haben hingegen sehr stark gegliederte Formationen („Labyrinthkerne”). Diese Kernsegmentierung ist für das Dermatofibrosarcoma protuberans ein morphologisches Korrelat seiner Semimalignität. Eine Klassifizierung der faserbildenden Tumoren als „fibröse Histiozytome” erscheint aufgrund der ultrastrukturellen Analyse nicht gerechtfertigt.
    Notes: Summary A report on the ultrastructure of the following skin tumors: dermatofibroma (7 cases), histiocytoma (4 cases), dermatof ibrosarcoma protuberans (1 case), and fibroxanthoma (1 case). Because of their different ultrastructural characteristics a division into two groups is possible: one group of tumors would include dermatofibroma, dermatofibrosarcoma protuberans, and fibroxanthoma, where the formation of fibers is extensive and fibroblasts are suggested for its histogenesis. These types of tumor differ from histiocytoma, the cellular character of which is determined by a very pronounced phagocytosis and storage of lipid and hemosiderin; a histogenesis from histiocytes is probable. The nuclei of dermatofibroma and histiocytoma show a simple surfacedevelopment, whereas the nuclei of dermatofibrosarcoma protuberans and fibroxanthoma show multisegmented nuclei (“labyrinth nuclei”). In the case of dermatofibrosarcoma protuberans this kind of nuclear segmentation seems to be a morphologic correlate of its semimalignancy. Based on ultrastructural analysis a classification of these fiber-producing tumors into “fibrous histiocytomas” is not justified.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 367 (1975), S. 171-179 
    ISSN: 1432-2307
    Keywords: Kidney failure ; Pregnancy ; Electron microscopy ; Hemolytic-uremicsyndrome ; Basement membrane ; Endothelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinico-pathological data from a patient with irreversible post-partum renal failure (IPRF) are presented. The electron microscopy of the late changes are described for the first time and consists of: 1. Thickening of the basement membrane. 2. Interposition of mesangial cells and matrix between the thickened basement membrane and the endothelial cell encircling the periphery of the tuft. 3. Multiplication of basal lamina material between mesangial cells and endothelial cells. 4. Proliferation of endothelial cells. All of the above changes tend to obliterate the glomerular tufts and transform the vascular lumina into slit-like spaces. They explain morphologically why most patients with IPRF terminate in chronic renal failure, if they survive the early changes. The late occurring hypertension is regarded as a secondary stimulation of the renin-angiotension system caused by partial or complete occlusion of arteries and arterioles.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 369 (1975), S. 111-121 
    ISSN: 1432-2307
    Keywords: Atherosclerosis ; apoB ; LDL ; VLDL ; Immunoperoxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine-structural localization of apoB, the major protein constituent of both the low and very low density plasma lipoprotein fractions, was described in human middle cerebral and basilar arteries. Using an immunoperoxidase technique together with electron microscopy, apoB was localized only in arteries with atherosclerotic involvement and to the following regions in these arteries: 1. on the outer aspects of extracellular spherical structures with diameters of 250 to 700 Å found predominantly in lipid cores and between bands of collagen fibers of advanced atherosclerotic lesions; 2. on the surface of reduplicated elastica; 3. along collagen fibers and; 4. on aggregates of extracellular spherical lipid globules. These results suggest that the extracellular spheres may represent the fine-structural morphology of deposited low and very low density lipoproteius and that free apoB may be bound to lipid globules, elastica, and collagen fibers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1975), S. 225-243 
    ISSN: 1432-0568
    Keywords: Differentiation ; Sympathetic ganglion ; Culture ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immature sympathetic ganglia prepared from 51/2- or 6-day-old chick embryos were cultured up to one month. The in vitro development was followed by phase microscopy, electron microscopy and using histochemistry for catecholamines, monoamine oxidase and cholinesterases. During the first week of culture extensive plexuses of nerve fibres were formed between and around the clusters of nerve cells. Mature-looking neurons were observed in the cultures by phase microscopy after three weeks, at which age the mean diameter of the perikarya was more than doubled. Varying catecholamine fluorescence was observed in the perikarya during the entire culture period. The nerve fibres showed usually only weak fluorescence, but, in the older cultures, bright varicosities were regularly found in the fibres. Monoamine oxidase activity was demonstrated already at three days of culture and the reaction was maintained positive. Weak or moderate acetyl-cholinesterase activity was demonstrated in the sympathicoblasts and young sympathetic neurons and their processes. The axolemma showed acetylcholinesterase activity also around the nerve terminals containing small dense cored vesicles. Reactions for the non-specific cholinesterases were negative. Electron microscopy of the 30-day-old cultures revealed that the clusters of nerve cells consisted of mature sympathetic neurons, which contained large (60–200 nm) and small (35–60 nm) granular catecholamine-storing vesicles. Glial cells were almost totally lacking. Large numbers of nerve terminals containing both large and small granular vesicles were observed in the clusters, often in synaptic contact with the sympathetic neurons. It is concluded that the primitive sympathicoblasts are, in favourable conditions, capable of differentiation in culture up to mature sympathetic neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 146 (1975), S. 279-300 
    ISSN: 1432-0568
    Keywords: Retinogenesis ; Synaptogenesis ; Guinea pig ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A light and electron microscopic examination of retinogenesis in the fetal guinea pig has revealed an early development of synapses and photoreceptor cells. Differentiation of the neural retina begins around day 23 of gestation. By 34 days the retina reaches its maximum thickness. It differentiates an inner plexiform layer in which vesicle-containing processes and primitive synapses are evident. Synaptic ribbons are found in processes of this layer by 43–45 days of gestation. An outer plexiform layer develops within the neuroblast layer at 40 days of gestation; from its first appearance the outer plexiform layer contains synapses complete with synaptic ribbons. Receptor terminals of the α, paranuclear and β type are present well before birth. Photoreceptor cells form inner segments by 40 days; the formation of outer segments is indicated by 45 days but not widespread until 49 days. The retina appears mature by day 51–57. It is clear that the primate is not unique in the early differentiation of its retinal synapses relative to the time of maturation of its photoreceptor cells. The potential functional capacities of precocious retinae, and the mechanisms of synapse development are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 147 (1975), S. 177-187 
    ISSN: 1432-0568
    Keywords: Iris ; Melanogenesis ; Chicken embryo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The iris anlage of 2–10 and 15 days old chicken embryos were studied histochemically, and by both light and electron microscopy. Light microscopic serial sections showed that pigmentation began at the outer layer of the posterior eye pole and progressed from there forwards to the optic cup margin. The entire outer layer of the optic cup as well as the pupillary margin were completely pigmented by the 4th day of incubation. By the 10th day the posterior iris epithelium was totally pigmented. Electron microscopical studies showed that the first premelanosomes appeared at about the 3rd day of incubation in the anterior iris anlage with the exception of the pupillary margin. It could be shown that melanogenesis progressed through the following steps: premelanosomes, followed by tyrosinase activity in a Golgi-associated system of smooth endoplasmic reticulum (GERL) and small vesicles and finally differentiation of the melanosomes. The possible origin of the premelanosomes and the formation of melanin are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 147 (1975), S. 293-307 
    ISSN: 1432-0568
    Keywords: Implantation ; Golden hamster ; Senescent ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Implantation was compared in young (3–5 month) and senescent (14–17 month) golden hamsters at 3, 31/2, 4, 41/2, 5, and 51/2 days of pregnancy (post-ovulation). One hundred twenty-two embryos (89 from 22 young females and 33 from 18 senescent females) located in utero by cutting thick sections (1–3 μm), were re-embedded and thin-sectioned for electron microscopy. Ultrastructurally implantation and embryonic differentiation was delayed approximately 12 hours in the senescent hamster when compared with young hamsters at the same stage of pregnancy. Failure of the blastocyst to implant would not appear to be a major cause of the declining litter size in aged golden hamsters.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 257-270 
    ISSN: 1432-0533
    Keywords: Perineurium ; Pathology ; Electron microscopy ; Homeostasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The response of the perineurium to the following experimental systems was investigated by light and electron microscopy: nerve crush, cold lesion and microinjection of (a) histamine liberator, (b) potassium cyanide, (c) lysophosphatidyl choline (LPC). Where myelin breakdown occurred, lipid globules were seen within Schwann cells, macrophages and also perineurial cells. Where increased vascular permeability occurred, proteinaceous material leaked from endoneurial vessels into the endoneurial space and later appeared between perineurial laminae. It is suggested that the normal homeostatic function of the perineurium is extended in pathology to the removal of protein and lipid debris. In this way the perineurium contributes to the restoration of the normal microenvironment of peripheral nerve fibres.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 106 (1975), S. 195-200 
    ISSN: 1432-072X
    Keywords: Trichophyton terrestre ; Trichophyton rubrum ; Hyphal fusions ; Origin of intra-hyphal hyphae ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cell observation chamber was designed to perform continuous photomicroscopic observations of hyphal anastomosis and the origin of intra-hyphal hyphae in Trichophyton terrestre and T. rubrum. These data were correlated with ultrastructural features of intra-hyphal hyphae. Hyphal fusions occurred commonly in either species of Trichophyton when incubated alone. In T. terrestre, empty hyphal segments adjoined by live units were invaded at the septa from both directions by new hyphal ingrowth. Continuous observations revealed that the intra-hyphal hyphae subsequently anastomosed via a lateral fusion peg. Similar intra-hyphal hyphae were shown in T. rubrum. Electron microscopic studies revealed ascomycetous septa in both conventional hyphae and intra-hyphal hyphae. For the latter, the cytoplasm and wall of the inner hypha were bounded by cytoplasmic organelles and another cell wall of the outer hypha.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 105 (1975), S. 193-199 
    ISSN: 1432-072X
    Keywords: Bean ; Rust ; Haustorium ; Sheath ; Autoradiography ; Infection ; Electron microscopy ; Phaseolus vulgaris ; Uromyces phaseoli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tritium labeled uredospores of Uromyces phaseoli were produced be feeding the host, Phaseolus vulgaris, with 3H-orotic acid. These spores were allowed to germinate on and to penetrate into a bean leaf. 24 hrs after inoculation, the bean rust had formed the first haustorium. All fungal structures, including the fungus walls, were heavily labeled. No label could be detected in the cells that had come into contact with the hyphae. In the infected host cell, the haustorium was labeled heavily, but the sheath around the haustorium and the host cell remained free of label. These results indicate that no detectable amounts of label leach from the bean rust into the host at this stage of infection although it is known that the rust takes up many metabolites. Since the sheath remains free of label and all fungal structures are evenly labeled, it is concluded that the sheath is formed by the host.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 1-8 
    ISSN: 1432-0533
    Keywords: Thalamus ; Cytoplasmic calcospherules ; Non-dystrophic ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Infantile thalamic degeneration is a rare clinico-pathological entity. Restricted location of the lesion and peculiar cytopathological changes serve to distinguish this disorder from other common encephalopathies. Optical and ultrastructural studies demonstrate cytoplasmic calcopherules in previously viable cells. According to current concepts of acute cellular reactions to injury and mechanism of intracellular calcification, the cytological changes cannot be attributed to either hypoxic ischemic cell change or dystrophic calcification. By analogy to other human and pathological material, the most likely basis for nondystrophic calcopherule formation is toxic or infectious injury with local synthesis, or autophagic or phagolysosomal degradation of cellular debris of specific chemical composition favoring calcium deposition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 143-152 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Experimental epilepsy ; Oedema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three different types of lesions have been studied in the cortex of the cat, by means of electroencephalography and electron microscopy. These three types of lesions can be listed in order of increasing magnitude according to their capacity to induce abnormal electrical activity: 1. incision of the cortex gives paroxymal activity, 2. intracortical insertion of a resin pellet generates weak epileptic activity, 3. intracortical insertion of a cobalt resin pellet produces epileptic activity. A parallel can be drawn between electrophysiological and anatomical data: there seems to be a quantitative relationship between the degree of epileptic activity and the extent of perilesional tissue. Furthermore, in this perilesional tissue, oedema is observed, the intensity of which varies according to the type of lesion. Thus, the epileptic activity of a lesion seems to be proportional not only to the volume of the perilesional tissue but also to the development of the oedema.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-0533
    Keywords: Adult metachromatic leukodystrophy ; Brain ; Peripheral nerve ; Kidney ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural characteristics of storage products in peripheral nerve, kidney and cerebral white matter, from a case of adult metachromatic leukodystrophy are described. There were pronounced differences from the fine structural aspects in late infantile cases. A large proportion of the inclusions did not exhibit a unit membrane. An hypothesis is proposed to clarify the delayed manifestation of this type of metachromatic leukodystrophy until adulthood.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 191-200 
    ISSN: 1432-0533
    Keywords: Niemann-Pick disease ; Storage distribution ; Cerebral vascular glycolipid ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A histochemical study is reported of regional differences of the lipid storage in a case of Niemann-Pick disease (NPD) type C. Besides tissues known to be affected (reticuloendothelium, hepatocytes, nervous system), storage was demonstrated in adrenal cortical spongiocytes, sweat glands, renal glomerular and tubular cells, smooth muscle, excretory tubules of some salivary glands, ependyma and in choroid plexus. In most tissues were stored sphingomyelin, cholesterol and a small amount of a glycosphingolipid. In the endothelium of cerebral and spinal vessels the main stored lipid was a glycosphingolipid. The significance of these regional differences are discussed and their study is recommended as a useful counterpart to the biochemical investigation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 343-349 
    ISSN: 1432-0533
    Keywords: Lafora disease ; Myocardium ; Deposits ; Enzame histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histological, histochemical and electron microscopic studies on the myocardium of 3 Japanese patients with Lafora disease were carried out. Deposits in the myocardium stained positively with PAS, Best's carmine and Lugol's indine. After digestion of the sections with α-amylase, the deposits disappeared or were less intense, in particular with PAS staining. Phosphorylase activity was deficient in the myocardium of Case 3, when compared with controls, both of which were kept frozen at −20°C following autopsy. Electron microscopy revealed that the deposits were not membrane-bound and consisted of fine particles and fibrillae. The nature of the deposits is diseussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 245-256 
    ISSN: 1432-0533
    Keywords: Herpes simplex encephalitis ; Blood-vessels ; Reactive microglia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Generalized vascular changes and diffused proliferation of reactive microglia were observed in an experimental model of HSV encephalitis of mice. The wide spread of these changes contrasted with the localized character of virus replication and the confined areas of damaged nervous tissue. The vascular and microglial changes were precocious in animals inoculated with concentrated virus suspension (105.5LD50) while they appeared late in mice inoculated with diluted virus suspension (100 LD50). After inoculation with U.V. inactivated virus no changes were seen. The results obtained in this study suggest that the vascular and microglial modifications are not related to a direct cytopathic effect of the virus but dependent on the amount of virus present in the central nervous system and linked to the virus DNA.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 275-278 
    ISSN: 1432-0533
    Keywords: Whipple's disease ; Macrophage ; Electron microscopy ; Brain involvement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A man of 22 with Whipple's disease suffered from an acute febrile state and unconsciousness. Focal inflammatory lesions accompanied by large numbers of peculiar macrophages occurred in thalamus and basal ganglia. The electron microscopic findings conform to previous reports on brain involvement in Whipple's disease.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 33 (1975), S. 207-226 
    ISSN: 1432-0533
    Keywords: GM2-Gangliosidosis, AB Variant ; Hexosaminidase A and B ; Electron microscopy ; Membranous cytoplasmic inclusions ; Zebra bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clinical and neuropathological studies of a case of AB variant GM2-gangliosidosis have been presented. The patient was a 14 months old black female infant who had “black cherry spot” in the retinas. The total activities of β-galactosidase and N-acetyl-β-hexosaminidase, as well as the proportion of hexosaminidase A and B components in her serum and leukocytes were normal when the assays were carried out with artificial fluorogenic substrate. Diagnosis of GM2-gangliosidosis AB variant was established by an abnormal increase of GM2-ganglioside in the biopsied brain tissue, similar to classical Tay-Sachs disease. Her clinical manifestation appeared to be similar but somewhat milder than those of classical Tay-Sachs disease. Light microscopic features of the cerebral biopsy were also closely similar to Tay-Sachs disease and Sandhoff disease but gliosis and neuronal loss were less pronounced. Electron microscopic study revealed numerous membranous cytoplasmic bodies (MCB) and zebra bodies in neurons. In addition, varieties of large intracytoplasmic inclusions in astrocytes, a feature distinctly different from classical Tay-Sachs disease, were observed. Numerous cytoplasmic inclusions were also present in oligodendroglia, pericytes and microglial cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 8 (1975), S. 319-331 
    ISSN: 1432-0630
    Keywords: Self-interstitials in silicon ; Swirls ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Point defect agglomerates in dislocation-free silicon crystals, usually called “swirls”, have been investigated by means of high-voltage electron microscopy. It was found that a single swirl defect consists of a dislocation loop or a cluster of dislocation loops. By contrast experiments it could be shown that these loops are formed by agglomeration of self-interstitial atoms. Generally the loops have a/2〈110〉 Burgers vectors, but in specimens with high concentrations of carbon (∼1017 cm−3) and oxygen (∼1016 cm−3) also dislocation loops including a stacking fault were observed. In crystals grown at growth rates higher thanv=4 mm/min no swirls are observed; lower growth rates do not markedly affect the size and shape of the dislocation loops. With decreasing impurity content (particulary of oxygen and carbon) the swirl density decreases, whereas the dislocation loop clusters become larger and more complex. A model is presented which describes the formation of swirls in terms of agglomeration of silicon self-interstitials and impurity atoms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 165 (1975), S. 245-249 
    ISSN: 1433-8580
    Keywords: Vinblastine ; Liver ; Perisinusoidal cell ; Microtubules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vinblastine, given intravenously to rats, leads to disappearance of microtubules, formation of paracrystalline inclusions and accumulation of fat droplets in the cytoplasm of the perisinusoidal cells of the liver suggesting that microtubules of the perisinusoidal cells play a role in lipid metabolism.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1432-0878
    Keywords: Avian follicles ; Oocytes ; Transosomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Production and fates of transosomes (sacs of ribosomes made in the follicular cells of an ovarian follicle and subsequently passed to the cytoplasms of the oocyte) have been studied by electron microscopy in ovaries of young chicks, a testosterone-treated hen, aged hens which had ceased laying eggs and a “non-layer” mutant. Study was also made of “primitive yolk” (vacuoles present in both follicular cells and ooplasms of small follicles of normally laying hens). It was found that both transosomes and vacuoles of primitive yolk were present in small oocytes of young chicks, and “non-layer” mutants. However, the transosomes deep within the ooplasms were present within lysosomal vesicles in both of these instances and the vacuoles containing primitive yolk were patently abnormal in the “non-layer” mutant. Very few transosomes or primitive yolk vacuoles were present within the ooplasms of follicles from a testosterone-treated hen or from those of aged hens which were no longer laying. In both of these latter cases such bodies were present in the follicular cells. However, many transosomes were seen to be in the process of being lysed within the cytoplasms of these follicular cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 163 (1975), S. 99-110 
    ISSN: 1432-0878
    Keywords: Central neuropile ; Planorbis corneus ; Synapses ; Spinule complexes ; Varicosities ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neuropile in the central ganglia of Planorbis corneus was studied by electron microscopy, using different fixatives. Several types of specialization were observed in the membranes of adjacent axonal processes, varying from only slight membrane thickenings to structures resembling desmosomes. Specialized structures similar to the ‘spinule complexes’ in mammalian brain are widely distributed in certain areas of neuropile. They consist of a small projection which invaginates a neighbouring neurone; the membranes are closely apposed and there is associated electron-dense material. The problem of identifying chemical synapses in this tissue is discussed. Many axonal processes are varicose, and it is suggested that varicosities may also be sites of transmitter release.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 163 (1975), S. 175-184 
    ISSN: 1432-0878
    Keywords: Cardiac sarcomeres ; Circolana borealis (Isopod) ; T-tubules ; Sarcoplasmic reticulum ; Couplings ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The membrane systems of the cardiac muscle cell of the isopod Cirolana borealis Lilljeborg are described. The sarcolemma invaginates at the level of the Z band, forming transverse tubules. Narrow tubules branch off in a longitudinal direction from these transverse and radially arranged TZ-tubules forming a transverse collar at each A-I level, where dyadic and triadic junctions are formed with the sarcoplasmic reticulum. Two different orientations of the coupling discs have been detected in the supercontracted sarcomere, and this observation has been discussed. Adjacent myofibrils are separated by a double layer of sarcoplasmic reticulum.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    ISSN: 1432-0878
    Keywords: Human spleen ; Sinus lining cells ; Pulp veins ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sinus and venous walls of normal human spleens were studied with enzyme histochemical and electron microscopic methods. Particular attention was paid to the connections between sinuses and veins. Histochemically the sinus lining cells revealed a distinct naphthol-AS-acetate-esterase activity but no reaction for alkaline phosphatase. Venous endothelial cells were positive for the latter but negative for the former enzyme. In the sinusvenous junctional area there were no endothelial cells with reactivity for both enzymes. Electron microscopically both the sinus lining cells and the venous endothelial cells could be clearly characterized and therefore easily distinguished from one another on morphological grounds. There were no clear ultrastructural indications of transitional forms between sinus lining cells and venous endothelial cells in the sinus-venous area. According to these findings, sinus lining cells represent a specialized endothelium, but one with practically no morpholgical similarities to the venous endothelium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 1432-0878
    Keywords: Epidermis ; Salmonids ; Mucous cells ; Mucus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of epidermal mucous cells of two species of salmonid fish has been described. Mucous cells are, next to filament-containing cells, the most commonly encountered cells in fish epidermis. The development of the cells as they progress to the periphery has been characterised. They are initially difficult to distinguish from filament-containing cells: later, they can be recognised by the presence of much smooth-surfaced E.R. The mucigenesis and the subsequent secretion of mucus has been observed and it is essentially comparable to that which occurs in the mucous cells of the mammalian intestine. The mucous layer of the epidermal surface seems to mainly comprise of the products of these mucous cells and the “cuticle” seen in other species has not yet been observed in the salmonid species investigated here.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 156 (1975), S. 201-216 
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Myofilaments ; Vas deferens ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Smooth muscle cells of the mouse vas deferens fixed with 5% glutaraldehyde contained three types of filaments, namely, thin (50–80 Å) filaments, intermediate (100 Å) filaments and thick (120–180 Å) filaments. However, in 2 out of 16 experiments, under identical conditions, the cells did not contain thick filaments. With OsO4 fixation, thin filaments were not prominent, the most obvious being thick (120–250 Å) and intermediate (100 Å) filaments. After soaking in a modified Ringer solution under no applied tension for one hour, thick filaments (120–180 Å) appeared prominently in smooth muscle cells of the mouse vas deferens and thin filaments were in ordered bundles. By 4 hours, thick filaments had increased in size and density, with thin filaments distributed randomly around them. After 8 hours in Ringer, thin filaments were diffuse and difficult to discern, while thick filaments were large (up to 300 Å) and electron-dense. Intermediate (100 Å) filaments were present in association with dark bodies. Physiological experiments indicated that the intracellular components responsible for the development of a mechanical response were still functional at this time. The presence of “thick filaments” is also reported in degenerating smooth muscle cells of the guinea-pig vas deferens in tissue culture.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 156 (1975), S. 411-416 
    ISSN: 1432-0878
    Keywords: Acrosome ; Spermatid ; Budgerigar ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the acrosome of the budgerigar spermatid was studied under the electronmicroscope. The acrosome arises from a granule derived from the Golgi apparatus which interacts with the nucleus to form a cone shaped acrosomal cap and a perforatorium. A quantity of cytoplasm and plasma membrane is captured from the cell periphery and incorporated into the substance of the acrosome. The possible significance of the developmental phases and comparative avian spermatology is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 156 (1975), S. 475-482 
    ISSN: 1432-0878
    Keywords: Annulate lamellae ; Spermatocytes ; Grasshoppers ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intranuclear and cytoplasmic annulate lamellae were studied in grasshopper spermatocytes (Melanoplus) with the electron microscope. Although cytoplasmic annulate lamellae were observed in all three species examined, intranuclear annulate lamellae were found in only one species. The intranuclear annulate lamellae encompass certain nuclear material adjacent to the nuclear envelope forming a vesicle that is extruded into the spermatocyte cytoplasm. In this same species, cytoplasmic annulate lamellae are seen contiguous with granular masses of varying size. These structures were noted as being morphologically indistinguishable from the “yolk nuclei” of dragonfly oocytes (Kessel and Beams, 1969; Kessel, 1973).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 158 (1975), S. 111-120 
    ISSN: 1432-0878
    Keywords: Iris ; Rana pipiens ; M. dilatator, sphincter pupillae ; Electron microscopy ; Photosensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The iris of the grass frog Rana pipiens, can respond to light even when isolated from the remainder of the animal. The iris is a three-layered structure, comprising a stromal layer and two layers of pigment epithelium. The sphincter pupillae, which is composed of pigmented smooth muscle cells, is embedded between the two layers of pigment epithelium. There is no dilator pupillae in this species. We have been unable to find any cells or any organelles in the iris which are anatomically specialized for photoreception in any obvious way.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 158 (1975), S. 205-213 
    ISSN: 1432-0878
    Keywords: Sertoli cell ; Crystalloid ; Swine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spindle or needle-shaped crystalloids are observed in Sertoli cells of the intersex and experimental cryptorchid swine in the light and electron microscopes. Small crystalloids are also observed in Sertoli cells of the normal swine only by electron microscopy. These crystalloids consist of fine filaments. The filaments are about 5 nm in diameter and arranged parallel to the long axis of the crystalloid. In cross sections of the crystalloid, the close packing of the filaments shows hexagonal arrays. The interfilamentous distance is about 5 nm. In all animals examined, bundles of short filaments, which are 5 nm in diameter, are observed in the basal part of the Sertoli cells. Ultrastructural similarities among the crystalloids, the bundles of fine filaments, and the filamentous layer in the junctional specialization of the Sertoli cell are shown. These morphological similarities suggest that the crystalloids are formed by the aggregation of the bundles in the Sertoli cells of azoospermic testes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 99-106 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method of calculating the conversion in Rony's hollow fiber reactor is outlined. It, is assumed that, the kinetics are of Michaelis-Menten type and that diffusion within the hollow fiber, as well as through its wall, should be taken into account. The normalization of the Thiele modulus suffices to unify the treatment of internal diffusion and the pseudosteady state hypothesis is found to be valid under almost all conditions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 119-128 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Immobilized glucoamylase, invertase, and β-galactosidase were prepared by using 2-hydroxyethyl acrylate and dimethylacrylamide under γ-ray irradiation. In the case of 2-hydroxyethyl acrylate, the monomer-enzyme solution was changed to the gel by irradiation of less than 1.0 Mrad, but it was difficult to eliminate enzyme leakage from the gel. When leakage was eliminated by increased irradiation, the activities of the gels were very low. In the case of dimethylacrylamide, the monomer-enzyme solution was changed to a gel by irradiation of 1.0 Mrad; leakage could be eliminated by irradiation of 2.0 Mrad. This gel possessed very high activity. In the case of acrylic acid-sodium acrylate, the monomer-enzyme solution could not be changed to a gel. In preparing gels, high concentrations of enzyme protein had a tendency to obstruct gelation.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 765-778 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The production of foot-and-mouth disease (FMD) virus in baby hamster kidney (BHK) suspension cells grown in serum-free media for subsequent use in vaccines was attempted because of the limited availability of serum in quantities sufficient for propagation of large amounts of cells, as well as the possible presence of mycoplasma, viral contaminants, and interfering antibodies in sera. Suspension cultures (50 to 600 ml) of BHK-21 cells adapted to and continually passed in a glutamine-free autoclavable, chemically defined medium (BHK-S system) were infected with all seven types of FMD virus. Cells were infected at multiplicities of infection (MOI) ranging from 10-1 to 10-7 plaque-forming units per cell (PFU/cell). The time course of infectious virus release and the amount of complement-fixing (CF) antigen produced were then followed. Peak harvest infectivities of approximately 108.5 PFU/ml were obtained from 12 to 24 hr after inoculation, depending on input MOI, and were apparently independent of cell concentration over the range 1.5 to 4.0 million cells/ml; the CF endpoint dilutions increased from 1:12 at the lower cell concentrations to 1:48 at the highest cell concentration. Monovalent and trivalent vaccines have been produced using viruses from the BHK-S system, inactivated with acetylethyleneimine and emulsified in oil, and the results of tests in steers and guinea pigs are presented.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 785-814 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The metabolic fate of drugs and other xenobiotics in mammalian organisms represents an area of intense contemporary interest. Traditionally, it is a difficult area of research becausethe biological systems which are used to study biotransformations are capable of yielding only minute quantities of metabolites. Recent developments in comparative biochemistry have made itpossible to link diverse metabolic systems through similarities in the pathways by which they alter foreign organic compounds. The potential thus exists for utilizing microbial metabolic systems to study and possibly predict the metabolic fate of a drug or other foreign compound in mammals. The ease with which microbial systems may be used to obtain large amounts of metabolites is an obvious Advantage.We havhe attemped to review the ways in which mammalian and microbialorganisms metabolize a variety of organic compounds. Attention has been focused on the similarities and differences in the mechanisms by which these living systems metabolize xenobiotics. Particular emphasis has been given to four types of reactions which are important in drug biotransformations: aromatic hydroxylationl; N- and O-dealkylations; and sulfur oxygenations.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 873-893 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A product inhibition model is developed to describe the hydrolysis of cellulose by the Trichoderma viride enzyme system. It is assumed that noncompetitive inhibition by cellobiose dominates the reaction kinetics. Experiments show that this is indeed a reasonable assumption for initial cellulose concentrations of up to 15 g/liter and at hydrolysis extents up to 65′. Kinetic parameters were determined for the noncompetitive inhibitionmodel in batch experiments with durations of up to 1.5 hr. These parameterswere then used in predicting reaction progress for up to 10 hr. Cellobiose was added to the reaction mixture at the onset of some runs and againreliable predictions were obtained for up to 8 hr of hydrolysis. Finally reaction was carried out in a membrane reactor whereby the product cellobiose was being continuously removed and again reasonable predictability was obtained with a higher net reaction rate.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1019-1027 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A microbial protease was immobilized by covalent attachment, to porous glass. This material was characterized for pH optimum, thermal stability, and operational half-life using casein as substrate.The immobilized enzyme was used for preparation of soya hydrolysates, low in free amino acids with high solubility.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1051-1064 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Recent findings in the author's laboratories relative to the determination of the mode of response of continuously cultured heterogeneous populations to step changes in pH and in temperature are reviewed and discussed in light of possible effects of specific growth rate, μ, on the severity of substrate leakage in the effluent during the transient phase.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1083-1098 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Values of the enhancement factor for oxygen absorption into fermentation broth, i.e., the ratio of the liquid phase mass transfer coefficients for oxygen absorption for both cases with and without respiration of microorganisms were predicted theoretically on the assumption of various cell concentration distributions. Calculations indicate that in the usual case the enhancement factor is only slightly or negligibly larger than unity, even when accumulation of microorganisms at or near the gas-liquid interface is assumed. Results of experiments with sparged-stirred fermentors on oxygen absorption into fermentation broths containing resting and growing cells of Candida tropicalis confirmed the theoretical prediction. Except for extreme cases, the effect of respiration of microorganisms on kLa, values can practically be ignored.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1029-1050 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A hollow fiber module was used as a reactor for conversion of ethanol to acetaldehyde in the presence of horse liver alcohol dehydrogenase as catalyst. Mass transport rates for NAD+, the overall acetaldehyde generation rate, catalyst effectiveness factors, and the overall order of the reaction with respect to NAD+ concentration were measured. A coupled-substrate reactor with continuous in situ regeneration of cofactor was also examined. Two substrates of opposite redox state were added simultaneously to the feed stream. NADH and acetaldehyde concentrations were monitored in the effluent stream. The cofactor recycle number, or ratio of moles of product to moles of NADH produced, exceeded 10,000 under certain conditions. While decreasing the NAD+ concentration in the feed stream decreased reactor productivity somewhat, it greatly enhanced the ratio of product formed per mole of NAD+ fed to the reactor. It is suggested that high cofactor costs in dehydrogenase reactors may be overcome with efficient in situ regeneration and secondary recovery and recycling of cofactor from the process stream.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1109-1118 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of CO2 on the formation of α-amylase by Bacillus subtilis NCIB 8646 growing in continuous and batch cultures was investigated.Different levels of CO2 examined in the batch cultures stimulated the formation of α-amylase, with the highest activity being obtained using 6% CO2(V/V). The additions of CO2 inhibit the growth and division ofvegetative cells of B.subtilis when CO2 is present in a concentration of more than 3%(V/V).In chemostat cultures, air containing 8% CO2 (V/V) increased the specific enzyme productivity almost three times over the control, without affecting the cell growth.An attempt is made to correlate the obtained results withthe already established theory for the regulation of the α-amylase synthesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1137-1156 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Purified enzymes and cell-free homogenates encapsulated by liquid-surfactant membrane have been shown to retain their catalytic activity (see previously published literature). This paper describes the preparation and properties of liquid-surfactant membrane-encapsulated whole cells of Micrococcus denitrificansATCC 21909. Batch and continuous studies with this model system have demonstrated that encapsulated viable cells reduce nitrates and retain their catalytic activity over anextended period of time. In batch operation, the reactivity of the encapsulated whole cells has been investigated under a variety of experimental conditions. The system is capable of reducing NO3- or NO2-. Data obtained indicate that encapsulated live cells have a broad pH and temperature optimum range. The encapsulated cells remain viable and do not “escape” into the external aqueous phase, even after five days of constant stirring with nitrate-containing simulated wastewater. Pulsed substrate addition experiments have demonstrated that the encapsulated cells also effectively reduce NO2- with no significant reduction in activity, even after 5.5 days of incubation at 30°C. The membrane selectivity for ion transfer has been achieved by incorporating oil-soluble ion exchangers in the membrane. Because of the protection of the liquid membranes, the catalytic reduction of NO2- by the encapsulated whole cells is not inhibited by 1 × 10-4 M mercuric chloride, which is otherwise extremely toxic to the cells, when present in the external aqueous phase. Continuous reduction of 20 ppm of NO2- by liquid membrane-encapsulated whole cells has been demonstrated in a constantly stirred reactor over a test period of about one week. In this paper we will discuss the reduction of NO3-and NO2- by the liquid membrane-encapsulated whole cells of M. denitrificansATCC 21909 mainly in batch runs undera variety of experimental conditions, such as cell and substrate concentrations, product and inhibitor permeation, pH and temperature, effect of oil-soluble ion exchangers on the substrate diffusion, etc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1291-1299 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Fermentations with mixed cultures of the cellulolytic fungus Trichoderma viride and the yeast Saccharomyces cerevisiae or Candida utiliswere examined. The fermentations were carried out in an aerated 5 liter fermentor with NaOH treated barley straw as the cellulose source (2-4%). Yeast was inoculated 24-32 hr after the fungus and the growth of the two organisms was followed through the production of CO2 and cell protein. In comparison with fermentations with T. viridealone, the production time for maximum yields of cellulases and cell protein was reduced by several days, depending on the straw concentrations. The protein content of the growth product was 21-22% and the amino acid composition of the product resembled that of T. viride alone.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1455-1465 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetic properties of α-galactosidase of Mortierella vinacea were investigated in detail using PNPG (p-nitrophenyl-α-D-galactopyranoside) as a substrate. Consequently, the enzyme was markedly inhibited not only by the substrate, but also by the galactose hydrolized. The initial rate of reaction at sufficiently high substrate concentrations, however, did not fall to zero and did approach a finite value. Galactose behaved as a mixed inhibitor and was neither totally competitive nor totally noncompetitive. A rate equation was obtained from a generalized equation derived from a kinetic model which took both the inhibitions into consideration. The constants used in the equation were appropriately estimated. The calculated rate agreed fairly well with the observed initial rate. Moreover, the PNPG hydrolysis progressing in a batch system was found to be approximately representable by simple first order kinetics in which the rate constant was dependent on the initial substrate concentration.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1515-1528 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To describe axial dispersion, particle film mass transfer, intraparticle diffusion, and the chemical reaction of the substrate for enzymes immobilized in porous particles in packed columns, we have developed mathematical models for first- and zero-order limits of Michaelis-Menten kinetics. Steady-state solutions were derived for both long and short column boundary conditions and for plug flow. Theory was compared to experiments of hydrolysis of sucrose catalyzed by invertase bound to porous glass particles. Steady-state conversions were measured for a range of flow rates. Pulse response experiments with inert packing were used to determine values of bed void fraction and particle porosity.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1697-1703 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1729-1747 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of whole-cell lactase of Escherichia coli immobilized in spherical agar gels was determined under the influence of interparticle mass transfer in a fixed bed reactor. The dependence of the pseudokinetic parameters (K′m and v′max) fluid conditions was in accordance with the prediction derived from combinedeffects of kinetics and mass transfer. Within the limited conditions of theexperiments, it was observed that the apparent Michaelis constant could be represented by the following simple equation, K′m/Km = 1 + (φ/kLa)(vmax/Km).The mass transfer coeflicient (kL) needed in the theoretical analysis was determined in correlation with particle size (0.12-0.45 cm) and liquid flow rate (0.30-12.0 cm/min) using the more stable enzyme, cell-bound invertase of Saccharomyces pastorianus, as the material to be entrapped in the gelatinous particles. The relationship was expressed in the following dimensionless equation, (1-φ)Sh = 2 + 0.6Re1/2Sc1/3, except that marked deviation resulting in the reduction of kL was noticed with a Reynolds number less than 0.8.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 203-210 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Enzymes can be sorbed on inorganic carriers followed by crosslinking with glutaraldehyde. In some cases superior results are obtained when the support is precoated with a porous layer of titanium oxide. Immobilized lactase prepared in this way retains essentially all its activity when stored under water at 23°C for long periods of time and loses activity only slowly while treating cheese whey at 55°C over the course of several weeks contact time. Furthermore, catalyst activity is unaffected by frequent sanitization. Optimum pH for these immobilized-lactase catalysts (enzyme produced from A. niger) is about 3.0 and optimum temperature is about 60°C. Amyloglucosidase catalase, L-asparaginase, and trypsin have also been immobilized by these techniques.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 167-184 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Following previous work in which a mass and monoxenous culture of Vorticella microstoma had been successfully established (Water Res., 7, 615 lpar;1973) another species of Ciliata, Colpidium campylum was subjected to continuous cultivation using Alcaligenes faecalis as the sole bacterial food and asparagine as the limiting substrate. This work was primarily undertaken to reveal the interaction and biological oscillation between these two types of organisms which simulate theecological behavior of activated sludge.The fact that the bacteria tended to flocculate and/ or deflocculate depending on the protozoan populastion density was incorporated into the rate equations to account for the oscillation in individual population density of the predator-prey system The mathematical approach presented earlier by canal and other workers forbiological oscillation used a homogeneously of the bacterial food wasoverelooked in the earlier publication.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 277-278 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 299-303 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Asbtract.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 291-293 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 305-314 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A potent inhibitory agent against human plasmin, fibrinolytic proteinase, has been found in the extracts of callus tissue of Scopolia japonica. Effects of cultural conditions on cell growth and production of the plasmin inhibitory substance by this cell line in suspension cultures were examined in MurashigeSkoog's medium. More than l.5 mg of the inhibitor, as t-amino cyclohexane carboxylic acid, a synthetic plasmin inhibitor, were observed to accumulate per ml of medium containing 0.83 g of NH4NO3 and 7.6 g of KNO3 per liter as well as suitable levels of growth hormones.Addiction of antibiotics and deformers were examined in preliminary tests for large scale cultivation. Semicontinuous culture on a small scale in a glass cylinder, was also tested and growth rate of 1.29 g/liter/day (by dry wt) was obtained. Plasmin inhibitory activities in the extracts of the results intact plant and in cultured cells of S. japonica were compared and the results indicated that cell suspension culture was superior to extraction the natural plant for inhibitor production.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 361-374 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The cellulase production by two strains of the cellulolytic fungus Trichoderma viride was examined. The fungi were grown on different preparations of barley straw pretreated with NaOH under high pressure. The production of cellulases and microbial protein by the better strain (QM 9123) was investigated in an aerated 5-liter fermenter under varying stirring rates (200-350 rpm) and straw concentrations (1-2%). The pH was kept between 3.5 and 4.5. The growth of the fungus was followed by measuring the quantity of CO2 produced and the cell protein. After 2-6 days growth ceased, the lag phases lasting 0-2 days, increasing with increasing straw concentrations. The maximum enzyme yields were reached after 4-10 days. The protein content of the product was 21-26% and up to 70% of the straw was utilized. The yield constants were calculated to be 0.40-0.56; of the same order as those which can be obtained by growing the fungus on glucose.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 441-444 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 451-453 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 461-462 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 481-497 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using whole cell invertase of Saccharomyces pastorianus, entrapped in spherical agar pellets, sucrose hydrolysis was carried out in a continuously fed fluidized bed reactor. The effective rate of reaction determined experimentally for the catalytic pellet was correlated with particle radius (R), intraparticle concentration of enzyme (Ep) and external concentration of substrate (SR).The results were elucidated by theoretical analysis incorporating internal mass transfer resistance. At high degrees of diffusional resistance, the effectiveness factor was successfully estimted from Bischoff's equation. A dimensionless number, mA = R(k2Ep/KmD)0.5(Km/(Km + SR)), was used conveniently to predict the effectiveness factor in those cases wher the intraparticle diffusional effect was less significant. This number was employed to determine critical pellet size for an optimal reaction.The relationship between the properties of the pellet (size and intraparticle enzyme activity) and its apparent kinetic constants (k′2 and K′m), estimated according to Lineweaver-Burk, are discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 527-539 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The dynamic characteristic of dissolved oxygen probes is usually modeled as being equivalent to a single diffusion layer. Other workers have shown that in response to a downstep in oxygen tension a polarographic probe initially follows single diffusion layer dynamics but that during the last 10% of response the probe deviates significantly from this behavior.Probe response to a series of downsteps of various magnitudes after exposure to calibration gases for 1, 2, and 3 min was recorded. When the probe membrane was new the response behavior was found to be largely independent of the step size as well as the exposure duration.The deviation fro the single diffusion layer model was explained in terms of lateral diffusion of oxygen from the anodic compartment to the cathode. By use of a model incorporating the lateral diffusion, probe response to a general oxygen tension-time function was calculated.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 571-583 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biokinetic parameters are usually calculated from slopes and intercepts taken from plots of experimental data. One response at an item is plotted and used for parameter estimation. Aside from problems that may be caused by transformations made when the data are plotted, this approach has the weakness of not using all the data simultaneously when there is more than one response. This paper shows how multiresponse biological data can be handled to get parameter estimates that are much more precise than those obtained using conventional methods.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 613-616 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 703-712 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Unbalanced growth has been studied in HeLa cell cultures maintained in perpetual division synchrony by periodic inhibition of DNA synthesis. Observation of eight independent cellular parameters indicates that once synchrony has been established the degree of unbalanced growth in later cycles is not as great as is observed with the conventional “double-block” technique. This significant diminution of unbalanced growth appears to be related to the significantly shorter periods of inhibition of DNA synthesis used in the resynchronization process.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 895-914 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A semi-quantitative theory is developed to explain the nonspecific binding of proteins to substituted affinity chromatography supports due to electrostatic and hydrophobic interactions. The equilibrium constant for the absorption of an enzyme to a solid support, and the rate of desorption of the enzyme are studied as functions of ionic strength. Experimental measurements were taken of the adsorption equilibrium constant and rate of desorption of E. coli β-galactosidase on Sepharose 4B substituted with 3, 3,-diaminodipropylamine in batch systems. It was found that the enzyme adsorption exhibits a hysteresis effect as the ionic strength is increased and then decreased. Furthermore, the adsorption of theenzyme becomes more reversible at the lower ionic strengths, while at the higher ionic strengths it is essentially irreversible. Using the measured equilibrium constants, and knowing the region of ionic strength where the adsorption becomes reversible, we were able to predict the desorption of enzyme in a continuous stirred tank as a function of time when a decreasing linear gradient of ionic strength was introduced into a slurry. It was found that the presence of another protein, hemoglobin, does not affect these results, and therefore can be separated from the enzyme.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 939-939 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 985-995 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An apparatus for the cultivation of microorganism under controlled conditions is described. This apparatus is basically a turbidostat improved with automatic devices for sample withdrawal and tube cleaning. The results of experiments, using Euglena gracilis to check the constancy of some physiological parameters (in particular phototactic reactivity), are reported.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 925-938 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The changes in several parameters of the candicidin fermentation (total, mycelium-associated, and extracellular product formation; growth rate; DNA content; glucose utilization; dissolved oxygen in the broth; and oxygen uptake rate) during the trophophase-idiophase transition are compared with previously reported data for the polyene macrolides, candidin and candihexin. The maturation time, tm, and the productformation rate constant, kp, have been calculated for each of the three polyene macrolides using a simple mathematical model. Slow-feeding of glucose, which resulted in candidin and candihexin overproduction has been shown to increase the polyene formation rate constant and toretard trophophase to idiophase transition (longer maturation time). The opposite effect is achieved by repeated feeding of soybean meal. The values of the maturation times and polyene formation rates obtained were used to predict the production of polyene macrolide antibiotics in batch cultures.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 997-1018 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model was developed to simulate, on a digital computer, the continuous fermentation of whey lactose to lactic acid with neutralization by ammonia. The simulation predicted the retention times for experimental test and the use of two stages for greatest efficiency. In the experimental tests, Lactobacillus bulgaricus was inoculated into whey in a 14-liter continuous fermentor at 44°C and with automatic pH control. A series of steady-state conditions was managed nonaseptically for 42 days without evident contamination and with an actual increase in the efficiency of conversion. Lactic acid was produced predominately' throughout the period, with less than 0.2% of other compounds. The product contained approximately 8 times as much crude protein (N × 6.25) as the original whey. In a single-stage fermentation at pH 5.5, a retention time of 15 hr resulted in a residual lactose concentration of 0.7%; and little improvement was realized by increasing the retention time. Increasing the pH to 5.8 resulted in a significant improvement, but further increasing the pH to 6.0 resulted in only a small additional gain. By the employment of two fermentors in series at pH 5.5 with a total retention time of 31 hr, the residual lactose was reduced to less than 0.1%. Lactic acid was produced as a function mainly of maintenance rather than growth metabolism.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1119-1135 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Anaerobic digestion offers a potential means of converting organic solid waste into fuel gas and thereby provide a supplemental and readily utilizable source of energy. We are particularly interested in the use of thermophilic digestion over a mesophilic operation for it can achieve higher rates of digestion, greater conversion of waste organics to gas, faster solid-liquid separation, and minimization of bacterial and viral pathogen accumulation. Our results comparing mesophilic (37°C) and thermophilic (65°C) anaerobic digestion of domestic solid waste confirm the increased rate and conversion of waste to methane. In addition, utilizing radioactive labeling of glucose and acetic acid, we have measured the volumetric rates of volatile acid production and disappearance under both mesophilic and thermophilic conditions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1383-1385 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstrast.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1421-1433 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Enzymatic hydrolysis of insoluble amorphous cellulose by Trichoderma viride cellulase was investigated in a batch reactor at several substrate concentrations and three enzyme levels. The reactions were carried out at 50°C and pH 4.8. Enzyme was rapidly adsorbed onto solids on contact, then gradually returned to the liquid phase as the reaction proceeded. A kinetic model that considered the fast adsorption which was followed by the slow reaction, and subsequent product inhibition was developed to interpret the experimental observations. The resulting equation successfully correlated the data for up to 70% conversion. The methods for determining the kinetic parameters are discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1443-1453 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A process for the utilization of modified whey syrups in wine alcohol fermentations is described. Palatable wines containing 10-12.5% alcohol were produced when various strains of S. cerevisiae var. ellipsoideus were fermented with hydrolyzed whey permeate syrups and grape juice concentrates. Experimental control of final alcohol and residual sugar levels in the wines by various chaptalization techniques is discussed. The possibility of utilizing this process in areas where both whey and grapes are abundant is mentioned.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1555-1559 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1591-1598 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The batch growth curves of Laclobacillus delbreuckii exhibit several exponential phases. From the results of a series of shaker flask experiments, the position of the slope changes in the growth curve and the overall bacterial yield is affected by the initial amount of yeast extract in the medium. It is postulated that this behavior is due to several growth enhancing substances that are initially in the yeast extract and are consumed by the bacteria during the course of the fermentation. Using a Monod-type expression to represent the effect of growth enhancing components in a proposed growth rate expression, a mathematical model of the system is set up and solved on the analog computer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1639-1662 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Simultaneous removal of organic materials and recovery of protein in the form of bacterial cells from a simulated high strength biodegradable wastewater was studied using thermophilic aerobic microorganisms. A naturally occurring mixed culture of thermophilic microorganisms was obtained from soil, wastewater, hay, silage, etc. A chemically defined medium containing glucose along with other essential nutrients was employed as the feed. The kinetic behavior of the culture was studied in a continuous culture at an optimum temperature of 58°C. Studies were also performed on the effects of solids retention time (SRT) on the observed cell yield and the protein and ash content of the harvested biomass. An economic analysis of the process or single cell protein recovery was given.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1783-1795 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Subtilisin BPN′ was immobilized to porous glass via isothiocyanate coupling. The pH optimum of the enzyme was shifted to the alkaline side on binding. This effect was more pronounced with ethyl lactate than with N-tosyl arginine methyl ester (TAME). Presumably, the shift is a reflection of the negative charge on the surface of the glass. The Michaelis constant and Vmax of soluble subtilisin BPN′ with TAME were two and one orders of magnitude, respectively, lower than with ethyl lactate. Vmax, calculated per g of active enzyme, with TAME as the substrate was not affected by immobilization, while Vmax with ethyl lactate decreased greater than tenfold. The apparent KM decreased on immobilization with ethyl lactate as substrate and increased with TAME. Results are explained in terms of diffusional resistance and a possible attraction of ethyl lactate to the glass surface. Active site titration indicated that about 25%, of the immobilized enzyme was active.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1827-1828 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1-13 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Trichoderma viride QM 9414 growth characteristics on glucose were investigated in single stage continuous stirred tank reactor operation and growth parameters μmax, Ks, QO2 identified. Multistage stirred tank fermentors in series with the first stage utilizing glucose and the subsequent stages utilizing cellulose yielded results in general agreement with theoretical predictions. Significant increase in enzyme productivity over single stage fermentation was obtained in multistage operation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 51-68 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The requirements for enzymic cofactor recycling have been investigated in a system employing alcohol and lactate dehydrogenases. The interactions of various combinations of free dehydrogenases or dehydrogenases immobilized either to the same or separate supports, with free NAD, a soluble highmolecular weight derivative of NAD or an insoluble derivative of NAD have been examined.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 129-142 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Rapid and extensive growth of Bacillus brevis ATCC 9999 was obtained in a complex medium containing yeast extract and peptone. Gramicidin S (GS) production in this medium reached 2.5 g/liter and 0.25 g/g dry cell weight. GS synthetase I production was also high in this complex medium. Chemically defined media were also developed for this strain. In a glycerol-ammonium sulfate-Tris-salts medium, the culture grew about 40% as well (rate and extent) as in complex medium. Although GS production was low (0.23 g GS/liter), peak specific activity of GS synthetase I was as high as on complex medium. Nutritional experiments showed that growth was stimulated by glutamine, methionine, proline, arginine, and histidine. Addition of these amino acids almost doubled the rate and extent of growth and GS production on a volumetric basis. However the increase in GS was due merely to the increased cell density; GS synthetase I specific activity was in fact decreased by the supplement. Complex medium is better than defined medium for GS and GS synthetase production due to increased cell density and a slower rate of synthetase disappearance.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. i 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 211-226 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method of solution to the problem of enzyme effectiveness factor has been presented. For a rapid estimation of the same, a graphical procedure is discussed which is sufficiently accurate for many practical situations. Applications to systems with rate dependent on position in the pellet and substrate and product inhibition is discussed. The case of concentration dependent diffusivity (facilitated diffusion) can also be solved by a simple transformation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 675-694 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An automated system for cell cycle analysis is described in which synchronous populations of greater than 95% mitotic cells can be selected and subcultured without resorting to inhibitors or altered media. Selection of mitotic cells from roller bottle cultures generates synchronous populations of up to 5 × 107 cells, as often as every 30 min, under conditions of constant temperature. A detailed analysis of the temporal pattern of DNA synthesis in the S phase of several Chinese hamster cells is presented. Several potential artefacts and uncertainties regarding the cell cycle blockage point in S phase synchronization are discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 745-764 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The growth of L-929 cells on a series of peptones, and protein hydrolysates was examined, and it was found that when MEM was supplemented with any of a series of peptones, cell growth was about as good as when serum was used as a supplement. Protein hydrolysates did not support cell growth very well and at higher concentrations actually reduced cell growth. L-929 and L-60TM cells were grown both as monolayers or stationary suspensions and in agitated systems in MEM supplemented with 0.5 - 1% bactopeptone. The addition of macromolecular compounds, insulin or oleic acid had no effect on cell growth. BHK cells were also grown on media supplemented with bactopeptone but richer media (MEM-alpha, F-12, or RMPI1640) gave higher cell yields. The cells did not form the monolayers observed with fetal calf serum, but a partial suspension system. Addition of a detergent Darvan #2 gave a totally suspension culture in both stationary and agitated systems.The production of Sindbis virus in BHK cells grown in serum-free media was examined and the yield of virus was found to be about the same as that produced in serum-supplemented systems. It is estimated that the cost of cell production media could be reduced by about 90% by the replacement of serum supplement by peptones.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. i 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 845-858 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Amongst the commercial type of homogenizers the Manton-GaulinAPV homogenizer (APV Company Ltd., Crawley, Surrey, England) which is generally being used for other purposes than cell disintegration processes, has recently been proved to be effective for the breakage of yeast cells. To understand fully the disintegration process occurring in such machines it becomes necessary to describe their functions through mathematical expressionsbased on a realistic hydrodynamic model.A mathematical expression describing the protein release at an applied pressure has been derived from an energy balance in the homogenizer combined with the size distribution function of yeast cell population. This expression has been confirmed experimentally under conditions where it shows that turbulence is the controlling factor in the system. Furthermore it indicates the area where more investigations are needed to improve the efficiency of the process of disintegration.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 859-872 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A natural microbial population of sewage origin was grown at four temperatures (10, 20, 30, 40°C) and five mean residence times (3, 6, 12, 18, 24 hr) in a continuous stirred tank reactor. Samples of cells were removed during steady-state operation and analyzed for chemical oxygen demand (COD), ash content, protein, carbohydrate, and nucleic acids. The oxygen equivalence (OE) of the cells was measured directly as g COD/g ash-free cells and was determined indirectly by calculating the calorific content from the macromolecular composition. The results indicate that OE is a function of growth conditions. Furthermore the COD test is a poor measureof OE because of a high level of variation associated with the test. Additional studies should be performed using bomb calorimetry to establish a quantitative relationship between growth conditions and OE.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1183-1197 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The imperfect state, Sporotrichum pulverulentum, of thecellulolytic basidiomycete Phanerochaete chrysosporiumhas been grown on barley flour and other agricultural products in shake cultures, in an air-lift fermentor, and in stirred fermentors. The growth morphology varied with cultivation conditions, but it was possible to maintain heavy suspensions of loosely associated mycelia in fermentors. The fungus can grow in temperatures up to 40°C and use ammonium salts or organic nitrogen sources to convert sugars, starch, pectin, and various seed residues to a biomass containing 30-40% protein with a favorable amino acid composition. Serial cultures were grown on flours under conditions where the larger part of the culture was withdrawn and replaced with new medium every, or every other, day. The mycelia are easy to harvest by filtration and have several properties which make the product attractive as a potential food ingredient.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1237-1242 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1245-1267 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The productivity of growth associated fermentations is dependent upon the quantity of biomass contained in the fermenter (microbial hold-up). In contrast, the performance characteristics of a fermenter are dominated by the form in which the microbial hold-up occurs, i.e., whether as films, flocs, or a combination of both. Industrial fermentations using biological films include biological waste-water treatment (trickling filter, rotating disc), the “quick” vinegar process, animal tissue culture, and bacterial leaching.Atkinson and Davies (Trans. Inst. Chem. Eng., 50, 208 (1972)), proposed a completely mixed microbial film fermenter (CMMFF) based upon the fluidized bed principle, for application to continuous operation when using growth associated systems. The potential performance characteristics of this fermenter are reviewed and the construction of a laboratory scale unit capable ofaseptic operation is described (volume 9 liters, maximum throughput 15 liter/hr). The fermenter has been continuously used for periods up to 2500 hr without contamination when growing brewer's yeast (NCYC 1026 flocculating). The experimental performance characteristics have been interpreted with the aid of the theory for the CMMFF.The knowledge and experience gained to date is used as a basis for speculation as to the future role of microbial film fermenters in the biochemical process industries.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1349-1361 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An attempt was made to find out the optimum aeration and agitation rates on the production of bacterial rennet from Bacillus sublilis K-26 using 5% wheat bran medium in a 13 liter fermentor. The enzyme activity and the growth rate were shown to increase with an increase in the rate of agitation. The fermentation experiments carried out at an agitation rate of 400 rpm showed an approximate threefold increase in enzyme activity with a considerable decrease in the fermentation time over those agitated at 200 and 300 rpm. The beneficial effect of a higher oxygen rate was observed for enzyme production occurring at a lower agitation rate. The inoculum activity and the varying amounts of antifoam agent which were added showed no apparent effect either on the total incubation time or on the final enzyme activity. It has been suggested that an agitation rate of 400 rpm with an aeration level of 3000 cc/min are the optimum values for the efficient production of bacterial rennet from B. subtilis K-26 using 5% wheat bran medium in a 13 liter fermentor.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1373-1374 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstrast.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1401-1419 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pancreatic lipase has been immobilized onto stainless steel beads by adsorption followed by crosslinking, and onto polyacrylamide by covalent bonding. The activities of the two types of immobilized enzyme toward the particulate substrate, tributyrin emulsion droplets, were determined experimentally, and rate constants based on Michaelis-Menten kinetics were calculated. The activity of the stainless steel-lipase was determined for various flow conditions and for various support sizes by the use of a differential fluidized bed recycle reactor. The rate constants calculated indicate that the experimental reaction rate is free from mass transfer influences, since the observed Michaelis constant does not vary with the fluidization velocity or with the support particle size. In addition, the Michaelis constant of the stainless steel-lipase was found to be equal to that of the free enzyme, suggesting that adsorption and subsequent crosslinking does not alter the enzyme-substrate affinity. The emulsion substrate mass transfer rates, calculated from the filtration theory, indicate that each substrate particle which contacts the immobilized enzyme is hydrolyzed to a significant extent. Theexperimentally determined kinetic rate constants may be used directly to predict the size of integral fluidized bed reactors.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1485-1514 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: L-Sorbose is oxidized to 2-keto-L-gulonic acid (KGA) via the following sequence of reactions which we call the “sorbosone pathway”: L-sorbose ⇌ L-sorbosone → KGA. The first step is reversible and is mediated by enzymes found in a soluble fraction obtained from Pseudomonas putida ATCC 21812. Although no cofactor requirements were found for the forward reaction, the reverse reaction clearly required NADH. Enzymes for this NADH-dependent synthesis of L-sorbose could be differentiated on the basis of molecular weights. The second step in the sorbosone pathway is catalyzed by a particulate enzyme found in extracts from P. putida and Gluconobacter melanogenus IFO 3293. The rate limiting reaction in the sorbosone pathway is the synthesis of L-sorbosone. In addition to P. putida, Klebsiella pneumoniae (ATCC 27858) and Serratia marcescens (ATCC 27857) also contain the enzymes which catalyze the reactions of the sorbosone pathway. Two of the bacteria studied, P. putida and G. melanogenus, also contain an enzyme involved in the further metabolism of KGA to L-idonic acid. This enzyme, referred to as KGA-reductase, is found in the soluble fraction of cell-free extracts and is dependent on NADH or NADPH.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1551-1554 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 17 (1975), S. 1571-1589 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Immobilized β-galactosidase gel was prepared using poly(vinylpyrrolidone) (PVP) under β-ray irradiation. In contrast to the gelation of N-vinylpyrrolidone monomer-enzyme solution, the gelation of PVP-β-galactosidase solution (PVP content: 10%) was almost completely uneffected by the dose rate and amount of phosphate present. PVP-enzyme solution was gelled by irradiation with 3.0 Mrad. The expressed activity of the PVP-enzyme gel was about 30% of the initial activity and added activity was almost totally entrapped. No leakage of enzyme from these gels could be detected. Leakage was, however, detected in the case of the gelation of PVP-enzyme solution containing more than 1% of enzyme protein. When the general properties of the gel were compared with those of the native enzyme, the gel proved to be slightly inferior to the native enzyme with respect to optimum temperature, heat stability, pH activity, and pH stability. Continuous hydrolysis of lactose in acid whey could be carried out at 50°C using a column packed with the gel and sawdust and the degree of hydrolysis was found to be almost, constant for 12 days. The merits of using PVP in the immobilization of enzymes include the simplicity of the procedure and the fact that the PVP-enzyme gel can be used in the food industry without anxiety because of its high degree of compatibility with living organisms.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...