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  • 1980-1984  (2,043)
  • 1970-1974  (926)
  • Biochemistry and Biotechnology  (2,211)
  • Electron microscopy  (757)
  • Nuclear reactions
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  • 1
    Electronic Resource
    Electronic Resource
    Peroxisomes in sebaceous glands (1984)
    Springer
    Anatomy and embryology 169 (1984), S. 261-270 
    Details
    ISSN: 1432-0568
    Keywords: Peroxisomes ; DAB-cytochemistry ; Electron microscopy ; Three-dimensional reconstruction ; Preputial gland ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of peroxisomes in partially differentiated cells of the mouse preputial gland was investigated using serial thin sections and three-dimensional reconstruction as well as the alkaline diaminobenzidine technique for visualization of the peroxidatic activity of catalase. An analysis of serial sections indicates that the different types of intensely stained peroxisomal profiles, classified according to their shape, represent random planes through highly complex peroxisomes. These organelles exceed 4 μm in length and exhibit a focal heterogeneity with respect to their size, shape and enzyme distribution. The graphical three-dimensional reconstruction demonstrates that the most intricate peroxisomes are characterized by tortuous, elongate, and branched tubular segments of varying diameter equipped with enlarged terminal hollow-spherical structures which engulf areas of cytoplasm. A close spatial relationship is established between adjacent peroxisomes and peroxisomes and mitochondria, the latter two of which synchronously develop into highly complex structures. A close association is also observed between peroxisomes and the endoplasmic reticulum, whereby membrane continuities between the two compartments cannot be demonstrated. These observations are inconsistent with traditional concepts concerning peroxisomal shape and size, the number per cell, as well as their biogenesis from the endoplasmic reticulum. The functional significance of individual highly complex peroxisomes and their assemblage forming an extensive netlike membraneous system throughout the cell is discussed with respect to intracellular energy transport and trans-membrane electron exchange.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315631
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructural studies of the temporal relationship between loss of zona pellucida and appearance of blastocyst-induced stromal changes during normal pregnancy in rats (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 45-49 
    Details
    ISSN: 1432-0568
    Keywords: Implantation ; Blastocyst ; Zona pellucida ; Decidual reaction ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural studies were undertaken to investigate the temporal relationship between loss of the zona pellucida around the blastocyst and the appearance of decidual changes in the endometrial stroma during normal implantation in rats. Blastocyst-free and blastocyst-containing sites of pregnant uterine horns were studied and compared with control sites from contralateral salpingectomized horns and horns of pseudopregnant animals from 24.00 h on Day 4 and onwards. There were no membrane contacts between the blastocyst and the uterine epithelium at 10.00 h on Day 5 and earlier because of an intervening zona pellucida. From 14.00 h onwards, however, such contacts were present and at 18.00 h, the zona pellucida had disappeared and the blastocyst had attached onto the uterine epithelium. The stromal cells of pregnant and control horns were indistinguishable from each other at 24.00 h on Day 4, but from 06.00 h on Day 5 onwards specific changes were noted in the stromal cell nucleoli of the pregnant horns. The results therefore suggest that the first morphological sign of decidualization occurs about 12 h before the Pontamine Blue reaction and is initiated by the blastocyst early on Day 5 while it is still encased by the zona pellucida.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319456
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  • 3
    Electronic Resource
    Electronic Resource
    Peroxisomes in sebaceous glands (1984)
    Springer
    Anatomy and embryology 169 (1984), S. 9-20 
    Details
    ISSN: 1432-0568
    Keywords: Peroxisomes ; Marginal plates ; DAB-Cytochemistry ; Electron microscopy ; Freeze-etching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the canine circumanal gland, the morphological alterations of peroxisomes during differentiation and maturation of the glandular cells were studied by electron microscopy, cytochemistry and freeze-etch technique. Each of the following three cell types has its own characteristic peroxisomal population: 1) The basal cell contains only a few small peroxisomes, which appear as spherical and tubular profiles showing strong DAB reaction. In the differentiating basal cells, these are joined by a few dilated, hemispherical organelles with intensely stained small marginal plates. 2) In the intermediate cell, additional to spherical and tubular peroxisomes, numerous clongated organelles with distinct marginal plates are observed, displaying weak catalase activity. 3) In the mature cell, dumbbell-shaped peroxisomes with enlarged marginal plates predominate. Serial section analysis and freeze-etching studies reveal that these dilated particles are of erythrocyte-like shape. They exhibit very weak catalase activity or do not contain any visible DAB reaction product. In their flattened, thin central portions, the memoranes enclose the marginal plates and form straight cisternae, which are closely associated with adjacent fenestrated cisternae of ER on both sides, referred to as paramarginal cisternae. Dumbbell-shaped peroxisomes with their corresponding paramarginal cisternae form large peroxisome-ER-complexes. Furthermore, three to five dumbbell-shaped particles are often stacked in parallel. Only at their flat poles are the organelles in close contact with paramarginal cisternae. The observation of continuities, in particular between erythrocyte-like organelles and tubular peroxisomes in mature glandular cells, indicates the existence of a peroxisomal compartment composed of two segments in the mature stage. In freeze-etch replicas of mature glandular cells, only the dilated segments of the peroxisomal compartment can be easily recognized because of their unusual size and erythrocyte-like shape. Additionally, on the E-face of their central portion, a straight, square or rectangular area with a distinct crystalline pattern is seen, which corresponds to the marginal plate. These findings indicate that the circumanal gland of the dog offers unique possibility to analyze the biological properties of a well-defined peroxisomal compartment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300582
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  • 4
    Electronic Resource
    Electronic Resource
    An ultrastructural study on the “meconium corpuscles” in rat foetal intestinal epithelium with particular reference to apoptosis (1984)
    Springer
    Anatomy and embryology 169 (1984), S. 119-124 
    Details
    ISSN: 1432-0568
    Keywords: Meconium corpuscles ; Apoptosis ; Foetal intestine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During the embryonic development of the intestine, programmed deletion of epithelial cells plays a vital role in the formation of secondary lumina and of villi. Electron microscopy shows that this deletion is effected by apoptosis, a distinctive mode of cellular death recently recognised as being implicated in normal tissue involution in the adult, as well as during intrauterine development. The process involves cellular condensation and budding to form membrane-bounded apoptotic bodies containing well-preserved organelles. These are then either engulfed by neighbouring principal cells or sloughed off into the intestinal lumen. Engulfed apoptotic bodies that show various degrees of lysosomal degradation have previously been reforred to as “meconium corpuscles”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00303140
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  • 5
    Electronic Resource
    Electronic Resource
    Hereditary motor and sensory neuropathy of demyelinating and remyelinating type in children (1984)
    Springer
    Acta neuropathologica 65 (1984), S. 1-9 
    Details
    ISSN: 1432-0533
    Keywords: Polyneuropathy ; Hereditary disease ; Chiloren ; Sural nerve biopsy ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten autosomal recessive/sporadic cases of hereditary motor and sensory neuropathy type I (HMSN I), nine of which originated from the northern part of Sweden, were included in the study. Parents were free from neurologic symptoms. Motor and sensory conduction velocity was normal when recorded, i.e., in 19 and 17 parents, respectively. Sural nerve biopsies from the ten cases revealed a varying degree of onion bulb formation. In eight of the cases the onion bulbs consisted of abundant basement membranes, whereas the Schwann cells were few and sometimes lacking. There were in some cases considerable differences between separate fascicles as to the loss of myelinated nerve fibers. In the six biopsies in which teasing was performed signs of present and previous demyelination were noticed. Numerous internodal segments were abnormally thin with reference to their length. In many such segments there were marked local thickenings of the nerve fiber. In cross sections the probable counterparts to these thickenings were nerve fibers with unduly thick myelin sheaths and complex folding of the myelin. Ultrastructural axonal changes were seen in the majority of the cases. The pathogenetic and diagnostic implications of the present findings are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689822
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  • 6
    Electronic Resource
    Electronic Resource
    Peripheral nerve findings in hereditary coproporphyria (1984)
    Springer
    Acta neuropathologica 63 (1984), S. 96-107 
    Details
    ISSN: 1432-0533
    Keywords: Hereditary coproporphyria ; Hereditary hepatic porphyrias ; Sural nerve biopsy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In spite of several cases reported in the literature, the exact pathogenetic mechanism of neuropathic changes in porphyric neuropathy remains uncertain. Various authors have ascribed the neuropathologic findings to either a dying-back axonal degeneration or segmental demyelination. In recent years, the hypothesis of an axonal and myelinic disorder has received support by the demonstration of a combined and simultaneous involvement of both these structures. Such different opinions are also a consequence of the reduced number of detailed bioptic observations in the different forms of acute porphyria not only during acute phases but also between attacks. In this paper we report the results of light- and electronmicroscopic examination of two sural nerve biopsies from subjects with hereditary coproporphyria. The first was performed 6 months after an acute attack, the second specimen was obtained from a patient without acute attacks, who had clinical and electrophysiologic signs of a chronic progressive neuropathy. In both cases a dying-back axonal degeneration is considered the primary change. The pathogenetic mechanism of peripheral nerve lesions in porphyric neuropathy will be discussed finally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00697191
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  • 7
    Electronic Resource
    Electronic Resource
    A possible paracellular route for the resolution of hydrocephalic edema (1984)
    Springer
    Acta neuropathologica 64 (1984), S. 122-128 
    Details
    ISSN: 1432-0533
    Keywords: Hydrocephalus ; Blood-brain barrier ; Tight junctions ; Paracellular pathway ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Considering the possibility of a paracellular route for edema resolution we studied the microvasculature of the subependymal and subcortical white matter in hydrocephalic rats. Normal adult rats were used as controls. After injection of kaolin suspension into the cisterna magna, the animals were killed at intervals of 1, 2, 4, and 8 weeks. In hydrocephalic rats at 1 week after kaolin injection, widening of the interendothelical cleft between the tight junction (dehiscence) was seen in 27 of 76 (35%) vessels. At 2 weeks after kaolin injection, the number of the dehiscences had increased (39/7:56%) and some were enlarged, forming interendothelial blisters. At 4 weeks in hydrocephalic rats, both dehiscences and blisters were still prominent (45/73∶63%) and at 8 weeks the dehiscences were still prominent, but the number of the blisters had decreased (25/81∶31%). The blisters and dehiscences were most pronounced in the corpus callosum and occipital regions. Following i.v. injection of horseradish peroxidase, the interendothelial dehiscences and blisters were completely devoid of the marker substance. These findings indicate that in obstructive hydrocephalus the tight junctions may constitute part of a paracellular pathway for the resorption of interstitial edema fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695575
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  • 8
    Electronic Resource
    Electronic Resource
    Axonopathy and microangiopathy in chronic alloxan diabetes (1984)
    Springer
    Acta neuropathologica 65 (1984), S. 128-137 
    Details
    ISSN: 1432-0533
    Keywords: Quantitative ; Electron microscopy ; Microangiopathy ; Pi granules ; Schwann cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A significant reduction in the myelinated nerve fiber population was observed during quantitative electron-microscopic examination of peripheral nerves in chronic alloxan diabetic rats. Dystrophic axonal abnormalities and regenerating fibers were more numerous in diabetics than age-matched controls. Schwann cells showed reactive changes including prominent pi granules of Reich and intracytoplasmic filament accumulation. Enumeration of these alterations, however, revealed no singificant difference from controls. Endoneurial macrophages in diabetic rats were also filled with lamellar intracytoplasmic inclusions characteristic of a chronic neuropathy. Quantitation of pathologic lesions in teased nerve fibers confirmed the preponderance of axonal over demyelinative disease and showed demyelination to be segmental. Microangiopathy was noted throughout the vasa nervorum of diabetic rats, and quantitative electron microscopy showed endothelial proliferation with doubling of the number of endothelial cells and proportional capillary mural thickening. Swollen, reactive endothelial cells appeared to effece the vascular lumen and may impair capillary perfusion. These microcirculatory changes, in the presence of biochemical and rheologic disturbances may contribute to tissue hypoxia and underly the loss of axons in experimental diabetic neuropathy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690466
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  • 9
    Electronic Resource
    Electronic Resource
    Hemiplegic atrophy (1984)
    Springer
    Acta neuropathologica 62 (1984), S. 324-331 
    Details
    ISSN: 1432-0533
    Keywords: Human skeletal muscle ; Hemiplegia ; Cerebral vascular disease ; Histopathology ; Electron microscopy ; Rehabilitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Anterior tibial muscle biopsies of the hemiplegic side of 16 patients with a cerebrovascular accident in the middle cerebral artery region were analyzed qualitatively and quantitatively by enzyme histochemistry and electron microscopy. Patients grouped according to the time lapsed as from the occurrence of the accident (1–17 months) demonstrated a progressive decrease in the fiber diameter and changes in fiber type distribution with predominant type II atrophy and type I predominance. Nuclear internalization, myopathic alterations, and perifascicular fatty infiltrations were observed constantly. In the affected fibers the ultrastructural findings were myofibrillar alterations with the formation of rods and cytoplasmic bodies. There was accumulation of lipofuscin, glycogen, and lipid droplets. Microvascular changes were observed frequently. Biopsies from the asymptomatic legs were either normal or showed age-related muscle alterations. Correlation was noted between the clinical and functional status of the patients and the morphological aspects seen in muscle biopsies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687615
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  • 10
    Electronic Resource
    Electronic Resource
    Ultrastructure of the wall of the Dandy-Walker cyst (1984)
    Springer
    Acta neuropathologica 62 (1984), S. 225-229 
    Details
    ISSN: 1432-0533
    Keywords: Dandy-Walker syndrome ; Dandy-Walker cyst ; Ependymal cell ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the wall of the Dandy-Walker cyst has been described rarely. A boy aged 2 years was confirmed clinically, neuroradiologically, and operatively as having a Dandy-Walker cyst in the posterior fossa. The cyst wall obtained during surgery consisted of an outer arachnoid cell layer, intermediate interwoven neuroglial strands, and an inner layer of cells which lacked the characteristic appearance of ependyma. An unusual finding was a small, buried island of ependymal cells in the intermediate layer of the neuroglial tissue. Ultrastructural study of the cyst wall provides a better understanding of the pathogenesis of the Dandy-Walker syndrome.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691856
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  • 11
    Electronic Resource
    Electronic Resource
    The use of semiautomatic morphometry in the study of normal rat gastrocnemius muscle fibers (1984)
    Springer
    Acta neuropathologica 64 (1984), S. 108-113 
    Details
    ISSN: 1432-0533
    Keywords: Image analysis ; Electron microscopy ; Muscle fibers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Based on a fixed number of EM photomicrographs a semiautomatic image analysis is made of normal gastrocnemius muscle fibers to obtain reference values for comparison with pathologic data. Z disc, mitochondria, tubular system, and sarcoplasmic reticulum are measured. It is stated that no definite fiber type differentiation is possible based on these quantitative data. However, measurements of Z disc and mitochondria are suggestive of such a differentiation. On the other hand, all data reach a Gaussian distribution on a logarithmic scale after a 5% correction factor is introduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695573
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  • 12
    Electronic Resource
    Electronic Resource
    Ultrastructure of carbon disulphide neuropathy (1984)
    Springer
    Acta neuropathologica 63 (1984), S. 255-263 
    Details
    ISSN: 1432-0533
    Keywords: Carbon disulphide ; Electron microscopy ; Giant axonopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult Wistar rats were exposed to carbon disulphide (CS2) vapour at a concentration of 2.4 mg/l of air for 5 days a week (6h a day), and the ultrastructure of peripheral nerves, neuromuscular junctions and muscles was investigated after 6 months of exposure to CS2. Numerous giant axons, i.e. paranodal or internodal swellings, were seen in the peripheral nerves. At the swollen paranodes, the myelin sheath was thinned, in other regions large intramyelinic vacuoles indicative of more dramatic demyelination were observed at axonal enlargements. Axonal enlargements consisted essentially of whorls of tightly packed neurofilaments. A number of nerve fibres underwent complete degeneration, but at the same time there was evidence of nerve regeneration. Nerve terminals were affected in a similar way following CS2 exposure. At neuromuscular junctions, filamentous swellings of nerve terminals preceded their degeneration and eventual denudation of synaptic gutters. As a rule, the postsynaptic part of neuromuscular junctions remained unimpaired by CS2 treatment. Muscles were affected by both atrophy and degeneration. Clusters of dense and lamellar bodies and numerous autophagosomes indicative of direct myotoxic effect of CS2 were frequently encountered in the investigated muscles. Some muscle fibres apparently underwent necrosis judging from the occurrence of myotubes characteristic of muscle degeneration and regeneration. The pathomorphology of CS2 neuropathy resembles that of other toxic neuropathies which presumably have a common origin in impaired energy metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685252
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  • 13
    Electronic Resource
    Electronic Resource
    A semiquantitative light and electron microscopic analysis of histopathologic changes in photochemotherapy-induced freckles (1984)
    Springer
    Archives of dermatological research 276 (1984), S. 2-11 
    Details
    ISSN: 1432-069X
    Keywords: Photochemotherapy ; Freckles ; Electron microscopy ; Melanocytes ; Langerhans cells ; Retinoid therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Photochemotherapy (PUVA)-induced freckles were found in 25 patients (41%) who had received more than 1,000 J/cm2 of PUVA. The patients had been treated with PUVA for more than 2 years, with more than 150 exposures before PUVA lentigines appeared on the thighs, the upper arm, the mid-lower arm, the waist, and the buttocks. The histopathology of these freckles was analyzed by light and electron microscopy. Light microscopy showed an increased amount of pigment and melanophages and increased numbers and size of melanocytes. The keratinocytes often displayed atypical features such as enlarged nuclei, giant size, or fibrillar degeneration. Homogenization of the papillary dermis was observed in 11 patients. The activation of melanocytes was confirmed electron microscopically, and pathological features such as large amounts of lipid droplets and lysosome-melanosome complexes within the melanocytes were seen. The Langerhans cells were mostly normal, whereas the keratinocytes showed cytolytic changes, fibrillar degeneration, and vacuolization. A close follow-up of patients with prolonged PUVA treatment is recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00412555
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  • 14
    Electronic Resource
    Electronic Resource
    Electron microscopic study on Langerhans cells and related cells in lymph nodes of DNCB-sensitive mice (1984)
    Springer
    Archives of dermatological research 277 (1984), S. 44-54 
    Details
    ISSN: 1432-069X
    Keywords: Birbeck granule ; Birbeck granule-like structure ; Electron microscopy ; Langerhans cell ; Lymph node
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To understand contact hypersensitivity, it is important to know the kinetics of Langerhans cells (LC) and related cells in the lymph node (LN), as well as in the skin. For this purpose, we tried experimentally to induce increased numbers of LCs, Birbeck granule-like structure (BgS)-containing cells, and interdigitating reticulum cells (IDC) in DNCB-sensitive mice and studied them by means of electron microscopy with the following results: (1) cytologically, LC, BgS-containing cells and IDC were closely related; (2) BgS seemed to arise from rough-surfaced endoplasmic reticulum (r-ER), and BgS-containing cells were midway in nature between LC and IDC from the morphological view point. From these findings, it appears that IDC, BgS-containing cells, and LCs were simultaneously involved in the contact hypersensitivity reactions of LNs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406480
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  • 15
    Electronic Resource
    Electronic Resource
    Structural analysis of EcoRI-DNA complexes as revealed by electron microscopy (1984)
    Springer
    Archives of microbiology 140 (1984), S. 265-270 
    Details
    ISSN: 1432-072X
    Keywords: EcoRI ; EcoRI-DNA complexes ; EcoRI* activity ; Recognition sites ; Frequency of binding ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Electron microscopy of negatively stained isolated restriction enzyme EcoRI revealed particle projections with triangular or square outlines, indicating that the enzyme, in its tetrameric state, is tetrahedron-like. The two dimers making up the tetramer appear to be arranged in two planes orthogonal to each other. Complexes formed by EcoRI with the plasmids pBR322 or pGW10 were investigated by electron microscopic spreading techniques. In the presence of Mg2+, EcoRI was bound to the DNA molecules to form pearl necklace-like aggregates. The number of bound EcoRI particles was much higher as the sum of EcoRI-and 5′..AATT..3′ sites (with exceptions, the 5′..AATT..3′ sites may function as one type of EcoRI* sites) along the DNAs, indicating unspecific binding. In the absence of Mg2+, EcoRI was bound to the DNA only at the recognition site for EcoRI and the sites where the tetranucleotide sequence 5′..AATT..3′ was present. A direct correlation of the local concentrations of the bases A and T within the flanking sequences of the binding sites with the frequency of EcoRI to the DNA was observed. Dimers and tetramers of the enzyme was found to bind to the DNA. Tetramers occasionally exhibited two binding sites for DNA as indicated by the observation of DNA loops originating at the sites of bound tetrameric EcoRI particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454940
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  • 16
    Electronic Resource
    Electronic Resource
    Site of action of the natural algicide, cyanobacterin, in the blue-green alga, Synechococcus sp. (1984)
    Springer
    Archives of microbiology 138 (1984), S. 273-277 
    Details
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Secondary metabolite ; Allelopathy ; Photosynthesis ; Electron transport ; Thylakoids ; Herbicides ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cyanobacterin is a secondary metabolite produced by the cyanobacterium, Scytonema hofmanni. Highly purified cyanobacterin was found to inhibit the growth of many cyanobacteria at a minimum effective dose of 2 μg/ml (4.6 μM). The antibiotic had no effect on eubacteria including the photosynthetic Rhodospirillum rubrum. The site of action of cyanobacterin was further investigated in the unicellular cyanobacterium, Synechococcus sp. Electron micrographs of antibiotic-treated Synechococcus cells indicated that cyanobacterin affects thylakoid membrane structure. The antibiotic also inhibited light-dependent oxygen evolution in Synechococcus cells and in spheroplasts. These data support our conclusion that cyanobacterin specifically inhibits photosynthetic electron transport. This activity is similar to herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU). The anhydro analog of cyanobacterin had no biological activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402134
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  • 17
    Electronic Resource
    Electronic Resource
    Histoenzymological and ultrastructural study of a bifocal calcifying epithelial odontogenic tumor. characteristics of epithelial cells and histogenesis of amyloid-like material (1984)
    Springer
    Virchows Archiv 403 (1984), S. 67-76 
    Details
    ISSN: 1432-2307
    Keywords: Calcifying epithelial odontogenic tumor ; Electron microscopy ; Histoenzymology ; Ameloblast ; Amyloid-like substance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A calcifying epithelial odontogenic tumor, simultaneously located in the two jaws (maxilla and mandible) was examined by histochemical and electron microscopic methods. Squamous tumor cells without secretory polarity were different from those of common ameloblastoma. High activities of alkaline phosphatase and ATPases were demonstrated by light and electron microscopy on the cytoplasmic membrane, findings similar to those in the stratum intermedium cells of the normal dental germ from which these tumor cells seem to arise. The tumor cells, like preameloblasts of the dental germ, also produce a granulo-filamentous material in intracytoplasmic vesicles and discharge it into the stroma. This “pseudo-amyloid” substance represents an abnormal protein of the enamel matrix and calcification, mainly occurring in that substance, might be an attempt at mineralization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689339
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  • 18
    Electronic Resource
    Electronic Resource
    Distribution of collagen types I and III and basal lamina in human gastric carcinoma: An immunohistochemical and electron microscopic study (1984)
    Springer
    Virchows Archiv 403 (1984), S. 313-322 
    Details
    ISSN: 1432-2307
    Keywords: Gastric carcinoma ; Scirrhous carcinoma ; Collagen ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Collagen types I and III were examined immunohistochemically in 32 cases of gastric carcinoma classified as poorly differentiated adenocarcinoma with scirrhous stroma, well differentiated adenocarcinoma with intermediate stroma, or poorly differentiated adenocarcinoma with medullary stroma. In the stroma of scirrhous carcinoma, types I and III collagens were distributed abundantly in fibrillar or granular patterns with little difference in the intensity of staining. In well differentiated adenocarcinoma, type I collagen was diffusely distributed in the stroma with type III collagen distributed sparsely. In poorly differentiated adenocarcinoma with medullary stroma, the two types of collagen were only found around capillaries, constituting the tumor interstitium. Electron microscopic examination of scirrhous carcinoma showed tumor cells partially covered with fibroblasts, and discontinuous basal lamina, collagen fibers and microfibrils present between tumor cells and fibroblasts. In well differentiated carcinoma, tumor cells were surrounded by fibroblasts, and well developed basal lamina was observed beneath the tumor cells. In poorly differentiated carcinoma with medullary stroma, the stroma consisted of capillaries and very few fibroblasts with discontinuous basal lamina occasionally being present between tumor cells and fibroblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00737282
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  • 19
    Electronic Resource
    Electronic Resource
    Elephantiasis neuromatosa (1984)
    Springer
    Virchows Archiv 404 (1984), S. 427-434 
    Details
    ISSN: 1432-2307
    Keywords: Elephantiasis neuromatosa ; Neurofibromatosis ; Electron microscopy ; Immunohistochemistry ; S-100 protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An example of elephantiasis neuromatosa, an unusual variant of neurofibromatosis, coexistent with lipomatosis is presented. This dual cell population produced a diffuse swelling of the gluteal sulcus of a young female. The neurogenous origin of the spindle cell component was substantiated by immunoreactivity for S-100 protein as well as by the fine structural observation of a regular basement membrane coating and a profusion of Luse bodies. As far as can be ascertained, this is the first reported immunohistochemical and ultrastructural study of this particular variant of peripheral nerve sheath lesion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695226
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  • 20
    Electronic Resource
    Electronic Resource
    Ellipsoids in the human spleen (1984)
    Springer
    Virchows Archiv 403 (1984), S. 27-40 
    Details
    ISSN: 1432-2307
    Keywords: Spleen ; Ellipsoids ; Morphometry ; Electron microscopy ; Lymphocyte traffic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study of ellipsoids (EL) in the human spleen was done on 25 surgically resected specimens in order to assess the number of EL, their structure, the nature of the cuff cells and the problem of lymphocyte traffic through their wall. The results show that an average spleen of 200 g contains 1.6 × 107 EL. They are localized in a constant segment of the vascular tree, just at the transition of the penicillary arterioles into capillaries and they consist of a capillary (not an arteriole) surrounded by a cuff of cells. These cells are neither endothelial nor smooth muscle cells, display lysosomal activity and are considered as fixed specialized pericapillary cells capable of cytoplasmic expansion. Since their number is inconstant in different individuals and in different species they are considered to be dynamic histological structures. Because of the constant presence of lymphocytes in their walls we consider the EL to be a transit system for lymphocytes and the splenic equivalent of the high endothelial venules in the lymph nodes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689336
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  • 21
    Electronic Resource
    Electronic Resource
    Granular cell tumour of the mammary gland simulating malignancy (1984)
    Springer
    Virchows Archiv 403 (1984), S. 391-400 
    Details
    ISSN: 1432-2307
    Keywords: Immunohistochemistry ; Electron microscopy ; Light microscopy ; Granular cell tumour ; Mammary gland neoplasm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary granular cell tumours of the breast in 35 2and 55 year old women were studied by light microscopy, transmission electron microscopy and immunohistochemistry. Light and electron microscopy revealed a neural origin of the tumours and this was further substantiated by immunohistochemical studies, with positive S-100 protein reaction and negative reactions for surface heavy and light chains, CEA, alfa-1-antitrypsin, muramidase and GFA-protein. Granular cell tumour of the mammary gland is a very rare tumour. Clinically it sometimes simulates carcinoma because of its fibrous consistency, fixation to pectoral fascia and skin retraction. The diagnosis of granular cell tumour should be included in the differential diagnosis of carcinoma of the breast. The granular cell tumour is derived from neuro-ectodermal tissue. Whether it represents a neurogenic cell-confined metabolic disturbance with lysosomal activation, or a true neoplasm remains to be elucidated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00737288
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  • 22
    Electronic Resource
    Electronic Resource
    Cytoplasmic inclusions and X-ray microprobe analysis in a case of prolymphocytic leukemia (1984)
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 229-232 
    Details
    ISSN: 1432-1335
    Keywords: Prolymphocytic leukemia ; Cytoplasmic inclusions ; X-ray microanalysis ; Chronic lymphocytic leukemia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A patient with prolymphocytic leukemia is described. The peripheral blood and bone-marrow cells contained nuclear pockets, bridges, and appendices, as well as cytoplasmic inclusions that were not membrane bound or connected with the endoplasmic reticulum. X-ray microanalysis of the cells showed them to contain large amounts of phosphorus, sulfur, chlorine, and calcium, as well as a smaller amount of sodium and magnesium in comparison with control lymphocytes. When compared with lymphocytes of a patient with chronic lymphocytic leukemia (CLL), the patient's cells showed higher amounts of magnesium, sulfur, and chlorine, while the sodium content was decreased. The usefulness of electron microscopy and X-ray microanalysis in the diagnosis of this type of leukemia is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01032613
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  • 23
    Electronic Resource
    Electronic Resource
    Epithelium of the human chorion laeve in diabetes mellitus (1984)
    Springer
    Virchows Archiv 402 (1984), S. 289-296 
    Details
    ISSN: 1432-2307
    Keywords: Epithelium ; Chorion laeve ; Diabetes mellitus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The epithelium of human chorion laeve from pregnancies complicated by diabetes mellitus was examined under the light and electron microscopy. In comparison with normal chorion laeve, the epithelium of chorion laeve in diabetes mellitus shows the following morphological changes: 1. The trophoblast cells display more microvilli and cell processes on their surface. 2. Trophoblast cells with different cytoplasmic characteristics can be seen. Some display few organelles and large glycogen depositions; other are rich in organelles. Furthermore, some cells with electron dense filaments and few cell organelles can be found. 3. Necrotic cells are frequently present in the outer epithelial layers. 4. The intercellular spaces in the epithelial layers near the basement membrane are narrower. Since vasculopathy of the decidual arteries with disturbance of blood circulation is often found in pathological pregnancies, we assume that the morphological changes found are due to deficiency in nutrient and oxygen supply.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00695082
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  • 24
    Electronic Resource
    Electronic Resource
    Phospholipase activity in human tumors: Localization by cytochemical staining (1984)
    Springer
    Journal of cancer research and clinical oncology 107 (1984), S. 242-244 
    Details
    ISSN: 1432-1335
    Keywords: Phospholipase ; Plasma membrane ; Cytochemistry ; Electron microscopy ; Human tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Phospholipase activity was localized for the first time by cytochemical staining at the plasma membrane of malginant cells in gastric adenocarcinomas by electron microscopy. This activity was not found in benign cells of the same tumor, e.g., in components of the connective tissue underlying the glandular epithelium, or in cells beyond the margin of the same tumor. Neither benign nor maligant cells of colorectal tumors, nor those in malignant melanoma, had any phospholipase activity that could be demonstrated by the method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01032616
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  • 25
    Electronic Resource
    Electronic Resource
    Ultrastructure and membrane permeability of cultured pancreaticβ-cells exposed to alloxan or 6-hydroxydopamine (1984)
    Springer
    Virchows Archiv 404 (1984), S. 31-38 
    Details
    ISSN: 1432-2307
    Keywords: Alloxan ; Culture ; Electron microscopy ; 6-Hydroxydopamine ; Pancreaticβ-cells ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stereological techniques on electron microscopy micrographs were used to evaluate the morphological changes of cultured isletβ cells that had been exposed to alloxan or 6-hydroxydopamine. Trypan Blue exclusion by cells cultured for 3 days indicated that the cells were 100% viable. Electron microscopy revealed that nearly all of the surviving cultured cells wereβ cells. Exposure to 5 mmol/l alloxan or 1–5 mmol/l 6-hydroxydopamine for 10 or 30 min caused a general swelling of the cultured cells with a concomitant swelling of mitochondria and nuclei. The size of the secretory granules was not affected by the drugs. Only 3–10% of the cells excluded Trypan Blue after exposure to 5 mmol/l alloxan or 6-hydroxydopamine. The data conform with the hypothesis that a primary action of alloxan and 6-hydroxydopamine is at the plasma membrane level ofβ cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704248
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  • 26
    Electronic Resource
    Electronic Resource
    Small cell neuroendocrine (oat cell) carcinoma of the male breast (1984)
    Springer
    Virchows Archiv 404 (1984), S. 213-221 
    Details
    ISSN: 1432-2307
    Keywords: Oat cell carcinoma ; Male breast ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of small cell neuroendocrine (oat cell) carcinoma of the breast in a 52-year old male is presented. Oat cell carcinomas have been reported in various extrapulmonary sites, but this is the second case of a primary oat cell carcinoma of the breast and the first one to have been documented in a male. The tumor was investigated histologically, immunocytochemically and ultrastructurally. The relationship to so-called “carcinoid” mammary tumors is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704065
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  • 27
    Electronic Resource
    Electronic Resource
    Distribution of concanavalin A binding sites on normal human urinary bladder mucosa and bladder tumors by transmission and scanning electron microscopy and x-ray microanalysis (1984)
    Springer
    Urological research 12 (1984), S. 135-141 
    Details
    ISSN: 1434-0879
    Keywords: Concanavalin A ; Lectin receptors ; Bladder tumor ; Electron microscopy ; X-ray microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We used concanavalin A (con A)-peroxidase-iron dextran-diaminobenzidine (DAB) technique for the electron microscopic detection of con A binding sites on cell membranes. Normal bladder mucosa showed a sparse distribution of con A binding sites with both transmission (TEM) and scanning (SEM) electron microscopy, but bladder tumors showed a higher concentration in the distribution of con A binding sites in proportion to the histopathological grade of transitional cell carcinoma. Quantitative estimation of the con A binding sites was attempted using scanning X-ray pulse analysis of iron elements contained in the reaction complexes. Con A binding sites were quantitatively the smallest in normal mucosa, increasing proportionate to the grade of the bladder tumor. Some specimens were compared by the ferritin-labelled method and the pattern of ferritin conjugates distribution was similar to that seen with the con A-peroxidase-iron dextran method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257180
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  • 28
    Electronic Resource
    Electronic Resource
    Electron microscopy of urinary calculi — Some facts and artefacts (1984)
    Springer
    Urological research 12 (1984), S. 17-22 
    Details
    ISSN: 1434-0879
    Keywords: Urinary calculi ; Electron microscopy ; X-ray microanalysis ; Artefacts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Material in urinary calculi is prone to irradiation damage during electron microscopy and this suggests the need for care in the interpretation of data. It is shown, however, that minimum-dose transmission microscopy is feasible for single-crystal electron diffraction work, and that although internal damage in severe, morphological artefacts are unlikely in the SEM unless the incident electron flux is greater than 10-13 A nm-2. During EDX micro-analysis, the detection of light elements is impaired by irradiation effects unless a minimum-dose procedure is used. For the preparation of SEM samples, artefacts can be created by cleaving air-dried material-and it is therefore important to consider more lengthy preparation methods such as cryogenics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00256304
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  • 29
    Electronic Resource
    Electronic Resource
    A study of the ultrastructure of urinary calculi by scanning electron microscopy (1984)
    Springer
    Urological research 12 (1984), S. 227-230 
    Details
    ISSN: 1434-0879
    Keywords: Urinary calculi ; Stone ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study of urinary stones obtained from patients after surgery in the Medical College Hospital, Trivandrum, under the scanning electron microscope showed the presence of calcium oxalate and calcium biphosphate crystals as the main constituents. However, the pattern of the different phases of crystal growth was not uniform. Within the crystal lattice, fibrous structures, possibly of protein matrix, were invariably observed. Electron microscopy may be usefully adapted as a particularly suitable method for ultramicroscopic investigation of the fine structure of urinary stones including single crystal surface structure, section of urinary calculi and for possible presence of hitherto unknown components within the calculus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00256809
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  • 30
    Electronic Resource
    Electronic Resource
    Cytochemical localization of adenylcyclase in the lateral wall of the inner ear (1984)
    Springer
    European archives of oto-rhino-laryngology and head & neck 240 (1984), S. 55-61 
    Details
    ISSN: 1434-4726
    Keywords: Inner ear ; Adenylcyclase ; Ouabain-insensitive endothelial ATPase ; Cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cytochemical localization of adenylcyclase in the lateral cochlear wall was studied using a modification of the Reik-Howell method. All the cell membranes of the stria vascularis and spiral prominence cells, except the vascular endothelium, showed a low enzyme activity. In the marginal cell and spiral prominence epithelium facing the endolymph, this activity was limited to the perilymphatic membrane sections. The results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464345
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  • 31
    Electronic Resource
    Electronic Resource
    Soil organic matter and structural stability: mechanisms and implications for management (1984)
    Springer
    Plant and soil 76 (1984), S. 319-337 
    Details
    ISSN: 1573-5036
    Keywords: Aggregates ; Aluminium ; Bacterial mucilage ; Binding agents ; Calcium ; Cation bridges ; Complexing agents ; Dispersion ; Electron microscopy ; Electrophoretic mobility ; Fungal hyphae ; Glues Iron ; Management Periodate ; Polysaccharides ; Rhizosphere ; Roots ; Slaking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The stability of pores and particles is essential for optimum growth of plants. Two categories of aggregates macro- (〉 250 μm) and micro- (〈250 μm) depend on organic matter for stability against disruptive forces caused by rapid wetting. Dispersion of clay particles from microaggregates is promoted by adsorption of complexing organic acids which increase the negative charge on clays. The acids are produced by plants, bacteria and fungi. However, the dispersibility of clay in microaggregates is offset by the binding action of polysaccharides, mainly mucilages produced by bacteria, but also by plant roots and fungal hyphae. The stability of microaggregates is also enhanced by multivalent cations which act as bridges between organic colloids and clays. Macroaggregates are enmeshed by plant roots, both living and decomposing, and are thus sensitive to management, and increase in number when grasses are grown and the soil is not disturbed. Lack of root growth,i.e. fallow, has the opposite effect. Various implications for management of soil structure are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02205590
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  • 32
    Electronic Resource
    Electronic Resource
    Biological and biochemical analysis of soils (1984)
    Springer
    Plant and soil 76 (1984), S. 127-137 
    Details
    ISSN: 1573-5036
    Keywords: Adenylate pool ; Biomass volume ; CO2 evolution ; Chitin ; DNA ; Electron microscopy ; Enzymes ; Fluorescent antibody ; Fumigation-respiration ; Fungi Histochemistry ; Imunofluorecence ; Jones-Mollison technique ; Microcosms ; Monoclonal antibodies ; Nitrogen ; Nutrients ; Oxygen consumption ; Phosphorus ; Phytotoxins ; Plate counts ; Rhizobium ; Rhizosphere ; Sulphur ; Xenobiotics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary There is an immense literature on biological and biochemical analyses of soils. Such analyses have revealed the enormous richness of species in soil and their vast range of metabolic potentials and ecological diversity. Accordingly, the approaches used to investigate the soil biota and its biochemistry usually have to be modified or adapted depending upon the purpose of the investigation. Studies of micro-organisms in the soil environment, are complicated because microbial cells are commonly attached to surfaces where they live side-by-side with other populations in consortia usually containing different morphological and physiological types. Such assemblages of organisms cannot be described quantitatively using cultural techniques, such as plate counts, which underestimate both cell numbers and viable biomass. The development of more powerful observational and staining techniques has improved our knowledge of the diverse morphological and biochemical composition of soil micro-communities. Such findings have been amplified at a grosser level by laboratory studies with multi-component systems (microcosms) to mimic field situations and to assess the range of biochemical potentials of microbial consortia. But despite notable advances in analytical methods we are still, with a few exceptions, unable to detect or identify those microorganisms which carry out specific biochemical transformations or determine whether particular cells are alive, dormant or dead at the time of observation. Considerable work has been done to define some of the fundamental ecological attributes of microbial assemblages in soil. Productive work on the metabolic activities of the soil microbiota, specially geochemical transformations of C, N, S and P, has been under way for more than a century. But only in more recent years have more sensitive and reproducible analytical methods become available to measure viable biomass in soil. This will enable some insight to be gained into the role that microbial biomass plays as a labile source and sink for plant nutrients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02205573
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  • 33
    Electronic Resource
    Electronic Resource
    Kinetics of formation of maltose and isomaltose through condensation of glucose by glucoamylase (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 121-127 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A kinetic model was devised for the hydrolysis and synthesis of maltose and isomaltose by two glucoamylases from Rhizopus niveus and Aspergillus niger, and the validity of the model was verified experimentally at 313 K and pH 5.0. For both enzymes, the formations of maltose and isomaltose from glucose were parallel reversible reactions, and glucosyl transfer between maltose and isomaltose was not observed. The enzymes catalyzed rapid hydrolysis and synthesis of maltose. Isomaltose was hydrolyzed and synthesized more slowly, but the level produced from glucose was much higher than that of maltose. These hydrolysis and condensation reactions were expressed well by the model.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260203
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  • 34
    Electronic Resource
    Electronic Resource
    Isolation of an inulinase derepressed mutant of Pichia polymorpha for the production of fructose (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 128-133 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pichia polymorpha has inulinase activity and could be used for the production of fructose syrup from inulin. The application of immobilized P. polymorpha whole cells for the continuous hydrolysis of inulin is, however, limited since the biosynthesis of this enzyme system is repressed by the reaction products, dextrose and fructose. A derepressed mutant hyperproducer of inulinase was isolated after treatment with EMS followed by a selection step with deoxyglucose.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260204
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  • 35
    Electronic Resource
    Electronic Resource
    Practical reactor systems for yeast cell immobilization using biomass support particles (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 134-141 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The technique of cell immobilization using porous support particles (biomass support particles) has been successfully applied to yeast cells. Two reactor configurations exploiting the use of these particles have been developed and assessed for use in aseptic yeast fermentations. A liquid-fluidized bed fermenter has been devised for use with particles denser than the fermentation liquor whilst a gas-stirred circulating bed fermenter proved suitable for particles of essentially neutral buoyancy. Both systems have been operated successfully for extended periods of continuous operation. The utilization of biomass support particle technology in such reactors provides a practical and robust system for immobilized cell reactors. This technology offers significant opportunities for further development.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260205
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  • 36
    Electronic Resource
    Electronic Resource
    Algal autoflocculation - verification and proposed mechanism (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 142-147 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biomass autoflocculation in outdoor algal cultures was found to be associated with increases of culture pH levels, due to CO2 consumption by the algal photosynthetic activity. Under these alkaline conditions, some medium chemical ions precipitated together with the algal biomass. The chemical substances involved with the process and its dependence on pH value were studied by simulation of autoflocculation in laboratory experiments. Proper concentrations of calcium and orthophosphate ions in the medium are important for autoflocculation and, in order to attain it within the pH range 8.5-9.0, the culture should contain 0.1mM-0.2mM orthophosphate and 1.5mM-2.5mM calcium prior to raising the pH level. Calcium phosphate precipitates are considered as the flocculating agent which reacts with the negatively charged surface of the algae and promotes aggregation and flocculation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260206
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  • 37
    Electronic Resource
    Electronic Resource
    Mathematical modeling of diffusion and reaction in the hydrolysis of vegetable protein in an immobilized enzyme recycle reactor (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 156-166 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental investigation is by far the most effective approach for studying the behavior of physical systems. However, an enzymatic solubilization of vegetable protein is a complex combination of intrinsic problems, of which many are not easily adaptable to experimental investigation. Experimental designs to study enzyme vegetable protein reactions yield data which describe the extramembraneous activity of the immobilized enzyme. In a continuous recycle immobilized enzyme reactor, the microenvironment concentration of the substrate or product in the membrane phase, or the concentrations along the reactor axial length in the bulk phase are not discernible to the experimenter. However, the knowledge of such concentration profiles is important in weighing the significance of such factors as intermembrane diffusion, enzyme loading, wet membrane size, and the mode of operation of the reactor. The simulation of mathematical models, which describe the physical system within the constraints imposed, yields information which is vital to the understanding of the process occurring in the reactor. The kinetics and diffusion of an immobilized thermophilic Penicillium duponti enzyme at pH 3.4-3.7 and 50°C was modeled mathematically. The kinetic parameters were evaluated by fitting a model to experimental data using nonlinear regression analysis. Simulation profiles of the effects of reactor geometry, substrate concentration, membrane thickness, and enzyme leading on the hydrolysis rate are presented. From the profiles generated by the mathematical model, the best operational reactor strategy is recommended.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260208
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  • 38
    Electronic Resource
    Electronic Resource
    Saccharification of untreated agrowastes during mycelial growth of mushroom Termitomyces clypeatu on solid beds (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 188-190 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260211
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  • 39
    Electronic Resource
    Electronic Resource
    A kinetic model for methanogenesis of acetic acid in a multireactor system (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 257-264 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bioconversion of acetic acid to methane by a crude culture of methanogens in a continuous multireactor system was investigated. Culture of methanogens was drawn from an active cow-dung digester (12 days) and was grown in a semisynthetic medium (pH 6.3, 37°C) with acetic acid as the sole carbon source. The solubilities of CO2, HCO3-, and CO32- increased with the rise in pH and exercised considerable influence on the gas composition. Various mechanisms for methanogenesis of acetic acid based on the available pathways were considered. Experimental data were compared with these mechanisms, the best fit was determined, and the corresponding rate expression was identified. This mechanism predicted that, of the total methane produced, 72%;comes from acetic acid directly and 28%;via the CO2 reduction route.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260310
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  • 40
    Electronic Resource
    Electronic Resource
    Cellobiose hydrolysis using Pichia etchellsii cells immobilized in calcium alginate (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 340-346 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The rate of celluose degradation, limited due to the inhibition by cellobiose, can be increased by the hydrolysis of cellobiose to glucose using immobilized β-glucosidase. Production of β-glucosidase in four yeasts was studied and a maximum activity of 1.22 IU/mg cells was obtained in cells of Pichia etchellsii when grown on 3% cellobiose as the sole carbon source. A study of the immobilization of β-glucosidase containing cells of Pichia etchellsii on various solid supports was conducted and immobilization by entrapment in calcium alginate gel beads was found to be the most simple and efficient method. A retention of 96.5% of initial activity after ten sequential batch uses of the immobilized preparation was observed. The pH and temperature optima for free and immobilized cells were the same, i.e., 6.5 (0.05M Maleate buffer) and 50°C, respectively. Even though the temperature optimum was found to be 50°C, the enzyme exhibits a better thermal stability at 45°C. Beads stored at 4°C for six months retain 80% of their activity. Kinetic studies performed on free and immobilized cells shown that glucose is a noncompetitive product inhibitor.The immobilized preparation was found to be limited by pore diffusion but exhibited no film-diffusion resistance during packed bed column indicated by a low dispersion number of 0.1348. A model for reaction with pore diffusion for a noncompetitive type of inhibited system was developed and applied to the cellobiose hydrolysis system. The rate of reaction with diffusional limitations was determined by using the model and effectiveness factors were calculated for different particle sizes. An effectiveness factor of 0.49 was obtained for a particle diameter of 2.5 mm. The modified rate expression using the effectiveness factor represented batch and packed bed reactor operation satisfactorily. The productivity in the packed bed column was found to fall rapidly with increase in conversion rate indicating that the operating conditions of the column would have to be a compromise between high conversion rates and reasonable productivity. A half-life of over seven days was obtained at the operating temperature of 45°C in continuous operation of the packed bed reactor. However, the half-life in the column was found to be greatly affected by temperature, increasing to over seventeen days at a temperature of 40°C and decreasing to less than two days at 50°C.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260408
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  • 41
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    Application of immobilized invertase to continuous hydrolysis of concentrated sucrose solutions (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 347-351 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Invertase immobilized onto corn grits was utilized in the hydrolysis of highly concentrated sucrose solutions producting liquid sugar solutions containing glucose and fructose. Comparisons of conversion efficiencies of this immobilized invertase in a continuous stirredtank reactor and a plug-flow reactor indicated that the plug-flow reactor has an higher efficiency. Continuous sucrose hydrolysis was then performed in 0.1- and 1-L tubular reactors. This tenforld scaling-up was achieved without any noticeable loss in efficiency. This process thus was scaled-up to a 17.6-L pilot reactor set in a cane sugar refinery. This reactor was fed with highly concentrated sucrose solutions [71% (w/w)] to produce invert sugar syrup with the desired inversion degree. It allows a productivity equal to 9.1 kg sucrose hydrolyzed/h in the case of a 69% (w/w) sucrose initial concentration with a 72% conversion rate.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260409
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  • 42
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    A model for the activated sludge process which considers wastewater characteristics, floc behavior, and microbial population (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 352-361 
    Details
    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 has been developed which describes organics removal, oxygen utilization, ammonianitrogen removal, ortho-phosphate removal, and biomass production in an aggregated microbial suspension containing a uniform floc size and the organics as a soluble biodegradable material. It is applicable to both steady-state and transient conditions, as well as to systems experiencing only carbon oxidation or to systems experiencing both carbon oxidation and nitrification. The model, consisting of five partial differential equations and four ordinary differential equations, takes into account the flow pattern in the reactor, intraparticle mass transport of oxygen, organics, ammonia-nitrogen and ortho-phosphate, and biochemical reactions by the individual cells embedded in the floc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260410
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  • 43
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    Continuous measurement of the ethanol concentration in fermenters by means of an infrared gas analyzer (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 390-391 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260418
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  • 44
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    Development of a computer control system for anaerobic methane-producing reactors (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 392-393 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260419
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  • 45
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    Immobilization of yeast pyridoxaminephosphate oxidase to halogenoacetyl polysaccharides (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 412-418 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pyridoxaminephosphate oxidase (EC 1.4.3.5, deaminating) that was partially purified about 40-fold from dry baker's yeast was immobilized to iodo- and bromoacetyl polysaccharides. The most effective carrier was an iodoacetyl cellulose, to which almost complete activity of pyridoxine 5′-phosphate oxidase was immobilized in 0.02M potassium phosphate buffer (pH 8.5) containing 2M ammonium sulfate at 4°C. The immobilized enzyme was more stable than the purified, soluble enzyme against heat and pH change. It was confirmed that N-(5′-phosphopyridoxyl)-L-serine was degradedly oxidized to pyridoxal 5′-phosphate and L-serine by the immobilized enzyme as comparable rate as pyridoxine 5′-phosphate, whereas N-(5′-phosphopyridoxyl)-D-serine did not serve as substrate, as in the purified, soluble enzyme.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260503
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  • 46
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    Plasmid stability in budding yeast populations: Dynamics following a shift to nonselective medium (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 814-819 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260732
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  • 47
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    Isomerization of glucose to fructose in a fluidized bed reactor (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 820-823 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260733
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  • 48
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    State of the art in fermentation air filtration (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 844-847 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article presents several characteristics of a state-of-the-art fermentation air filter. The filter medium is composed solely of PTFE and has an absolute pore size rating of 0.2 μm. Quantitative bacteria and bacteriophage retention is shown based on live organism challenge tests. A nondestructive filter test, correlated to the microorganism challenge tests and called the Forward Flow Integrity Test, is described. This test has a sensitivity of one part in 1012 and can be performed in situ.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260805
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  • 49
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    Sterilization of oils: Data to support the use of a continuous point-of-use sterilizer (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 848-856 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The continuous slow feed of animal and vegetable oils is frequently found to be an economically attractive method for maintaining antibiotic fermentations at a highly productive rate. The sterilization of oil feeds can present a major problem in the production plant. In this article, we present data and methodology on the kinetics of the thermal sterilization of No. 2 lard oil and soybean oil. It was also determined that dry heat sterilization condition could occur if dry spores were added to dry oil. This condition could only be partially alleviated by the addition of water to the oil. The theory and design of a small tubular coil continuous sterilizer for sterilizing oils at the point of use is also presented. This type of sterilizer is economical and versatile and simplifies control and instrument requirements. It provides a realistic alternative to the use of sterile feed tanks and sterile headers.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260806
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  • 50
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    Pilot-and production-scale containment of cytotoxic and oncogenic fermentation processesPresented at the 184 th American Chemical Society National Meeting Division of Microbial and Biochemical Technology. Kansas City, Missouri, September, 1982. (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 860-870 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Proper design of fermentation facilities and equipment modification can control the risks associated with largescale production and purification of microbially produced cytotoxic agents and oncogenic viruses. The primary biohazard risks to operators and the environment are generation of aerosols and accidental spills. Fermentation and recovery facilities can be constructed to contain these agents by installing fermentation equipment within a HEPA-filter-exhausted biological barrier. Within this barrier system, large-scale processing that generates potentially hazaradous areosols (filtration, centrifugation of transformed cells or crystal slurries, and banding of viruses) should be isolated from other operations. Isolation of equipment is often required, with provision for both chemical and biological decontamination of process wastes. Failsafe fermentor over-pressure sensors, parallel exhaust gas filtration, welded transfer lines, and modified sampling systems for elimination of aerosols can be installed on most fermentation equipment. Aerosol and spill containment by proper equipment design, coupled with appropriate personnel protective equipment and medical monitoring, make possible safe production of experimental growth factors and viruses from large-scale culture of transformed mammalian cells and production of cytotoxic antitumor antibiotics.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260808
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  • 51
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    Acidogenic and methanogenic fermentation of causticized strawMention of a commercial or proprietary product does not constitute a recommendation or an endorsement of this product by the U.S. Department of Agriculture. (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 885-891 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of pretreatment process variables [straw concentration between 20 and 90 kg volatile solids (VS)/m3, temperature between 30 and 85°C, and alkaline dosage between 0 and 80 g NaOH/kg VS] on acidogenesis and methanogenesis were investigated. Rates of acidogenesis and methanogenesis were determined using firstorder kinetics, and ultimate acid and methane yields were measured. The acid yield was not affected by pretreatment concentration or temperature, but increased as alkaline dosage increased. The acidogenesis rate was not affected by pretreatment temperature or alkaline dosage, but decreased as the substrate concentration increased. This decrease in the acidogenesis rate was attributed to a decrease in the inoculum: substrate ratio as the substrate concentration increased. The methane yield and methanogenesis rate were not affected by pretreatment substrate concentration or temperature, and both increased with alkaline dosage up to about 40 g NaOH/kg VS, then remained relatively constant above 40 g NaOH/kg VS.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260811
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  • 52
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    Immobilization of enzymes in porous supports: Effects of support-enzyme solution contacting (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 892-900 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Proteins have been immobilized in porous support particles held in a fixed-bed reactor through which protein solution is continuously circulated. Changing the recirculation flow rate alters the observed immobilization kinetics and the maximum enzyme loading which can be achieved for glucose oxidase and glucoamylase on carbodiimide-treated activated carbon and for glucoamylase immobilized on CNBr-Sepharose 4B. Direct microscopic examination of FITC-labelled protein in sectioned Sepharose particles and indirect activity-loading studies with activated carbon-enzyme conjugates all indicate that immobilized enzyme is increasingly localized near the outer surface of the support particles at larger recirculation flow rates. Restricted diffusion of enzymes may be implicated in this phenomenon. These contacting effects may be significant considerations in the scaleup of processes for protein impregnation in porous supports, since apparent activity and stability of the final preparation depend on internal protein distribution.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260812
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  • 53
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    Hydrolysis of milk lactose by immobilized β-galactosidase-hen egg white powder (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 901-904 
    Details
    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 was obtained by crosslinking the enzyme with hen egg white using 2% glutaraldehyde. The gel obtained could be lyophilized to give a dry enzyme powder. The pH optimum of both the soluble and immobilized enzyme was found to be 6.8. The immobilized enzyme showed a higher Km for the substrates. The extent of enzyme inhibition by galactose was reduced upon immobilization. The stability towards inactivation by heat, urea, gamma irradiation, and protease treatment were enhanced. The bound enzyme as tested in a batch reactor could be used repeatedly for the hydrolysis of milk lactose. The possible application of this system for small-scale domestic use has been suggested.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260813
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  • 54
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    Enzymatic hydrolysis of inulin to fructose by glutaraldehyde fixed yeast cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 905-910 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Inulin, a polyfruction, is found as the reserve carbohydrate in the roots and tubers of various plants (i.e. Jerusalem artichoke, chicory, and dahlia tubers). The β-fructofuranosidase (inulase) from the yeast Kluyveromyces fragilis is of interest because of its industrial potential in fructose syrup and alcohol production from inulin containing plants. We have found that the inulase of K. fragilis can be immobilized in the yeast cells by glutaraldehyde treatment. These cells are resistant to physical and enzymatic destruction. Although the exact nature of the immobilization is not fully understood, the kinetic parameters of the immobilized enzyme are similar to those of the soluble enzyme. No reduction of enzyme activity was observed after glutaraldehyde treatment and glutaraldehyde concentration did not affect enzyme activity. A 96% hydrolysis of dahlia inulin was achieved in 10.5 h with a 9.5% (w/v) fixed enzyme suspension. A Jerusalem artichoke extract containing 16.8%polyfructan was completely hydrolyzed in 3.5 h with a 0.24% (w/v)fixed enzyme suspension. This is a time frame feasible for industrial consideration.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260814
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  • 55
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    Cholinesterase-catalyzed resolution of D,L-carnitine (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 911-915 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An enzymatic method for the preparative resolution of racemic carnitine (whose L-isomer and its acyl-derivatives have numerous therapeutical applications) has been developed. It is based on our finding that electriceel acetylcholinesterase hydrolyzes the D- but not the L-isomer of acetylcarnitine. (Another cholinesterase tested, horse serum butyrylcholinesterase, is also stereospecific and hydrolyzes only the L-isomer of butyrylcarnitine.) Acetylcholinesterase, covalently attached to alumina, was employed for the resolution of D,L-carnitine; the latter was first chemically acetylated, then stereoselectively hydrolyzed with the immobilized enzyme, and finally the acetyl-L-carnitine and D-carnitine produced were separated by ion-exchange chromatography. Gram quantities of D,L-carnitine were thereby resolved.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260815
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  • 56
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    Control strategies of continuous bioprocesses based on biological activities (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 916-925 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Based on the material balance principle applied to microbial reactions in continuous bioprocesses, the concept of reaction rate control has been developed theoretically. This concept provides a more direct way of controlling biological activities than the control of physical or chemical parameters in practice today. From an analysis of dynamic and steady-state experiments, two control systems for carbon dioxide production rate control during the continuous culture of baker's yeast have been designed and evaluated experimentally. In these control methods, intracellular NADH concentration is used as an immediate indication of the onset of glucose repression. A more sophisticated master controller based on the respiratory quotient can be combined with these control methods. The resulting control system provides a means to indirectly optimize biomass production while preventing ethanol formation in the continuous culture of baker's yeast.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260816
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  • 57
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    The estimation of growth yield and maintenance parameters for photoautotrophic growth (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 926-935 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Methods are presented for examining the consistency of experimental data for microbial growth where light energy is converted to chemical energy through photosynthesis. True growth yield and maintenance parameters are estimated for several sets of available experimental data. Methods of parameter estimation are presented which allow all of the measured variables to be used simultaneously for parameter estimation. The results show that a wide range of values have been found for the true growth yield and maintenance parameters. Values of the true growth yield range from 0.04 to values above those predicted by the Z-scheme model for photosynthesis.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260817
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  • 58
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    A comparison of two empirical models for the enzymatic hydrolysis of pretreated poplar wood (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 936-941 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two empirical models for the enzymatic hydrolysis of cellulose are used to analyze the same set of experimental data to determine if one model is superior to the other. Both models adequately describe the data. The parameters in both models may be correlated to the hydrolysis conditions of enzyme, substrate, and product inhibitor concentrations. Both empirical models have features which are consistent with theoretical models of cellulose hydrolysis.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260818
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  • 59
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    An operational strategy for unstable recombinant DNA cultures (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 942-947 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A simple operational strategy is shown to offer a viable means of enhancing plasmid stability in chemostat systems where plasmid loss is a common problem. Feedback control can be used to stabilize coexistence states, which are naturally unstable in the system investigated, and thus gurantee retention of the plasmid-carrying strain. The strategy exploits the normally undesirable characteristics of substrate inhibited growth kinetics, and is illustrated with specific reference to methanolutilizing organisms. Since the methodology may be easily implemented in practice, it offers an alternative to costly environmental methods such as antibiotic addition.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260819
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  • 60
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    Enzymatic properties of immobilized Alcaligenes faecalis cells with cell-associated β-glucosidase activity (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 583-589 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Enzymatic properties of Alcaligenes faecalis cells immobilized in polyacrylamide were characterized and compared with those reported for the extracted enzyme, and with those measured for free cells. Many of the properties reflected those of the extracted enzyme rather than those measured in the free whole cells prior to immobilization, suggesting cell disruption during immobilization. These properties included the pH activity profile, a slightly broader pH stability profile, and the activation energy. Electron micrographs showed evidence of cell debris among the polymer matrix. The immobilized cells were not viable, and did not consume glucose. Thermal stability was less after immobilization with a half-life of 16 h at 45°C, and 3.5 h at 50°C. The immobilized preparation was more stable when stored lyophilized rather than in buffer, losing 23 and 52% activity, respectively, after six months. The enzyme was irreversibly inhibited by both acetate and citrate buffers. If the immobilized enzyme is to be used in conjunction with cellulases from Trichoderma reesei for cellulase saccharification, the optimal conditions would be pH 5.5 and 45°C in a buffer containing no carboxylic acid groups.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260604
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  • 61
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    Dephenolization of industrial wastewaters catalyzed by polyphenol oxidase (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 599-603 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new enzymatic method for the removal of phenols from industrial aqueous effluents has been developed. The method uses the enzyme polyphenol oxidase which oxidizes phenols to the corresponding o-quinones; the latter then undergo a nonenzymatic polymerization to form water-insoluble aggregates. Therefore, the enzyme in effect precipitates phenols from water. Polyphenol oxidase has been found to nearly completely dephenolize solutions of phenol in the concentration range from 0.01 to 1.0 g/L. The enzymatic treatment is effective over a wide range of pH and temperature; a crude preparation of polyphenol oxidase (mushroom extract) is as effective as a purified, commercially obtained version. In addition to phenol itself, polyphenol oxidase is capable of precipitating from water a number of substituted phenols (cresols, chlorophenols, naphthol, etc.). Also, even pollutants which are unreactive towards polyphenol oxidase can be enzymatically coprecipitated with phenol. The polyphenol oxidase treatment has been successfully used to dephenolize two different real industrial waste-water samples, from a plant producing triarylphosphates and from a coke plant. The advantage of the polyphenol oxidase dephenolization over the peroxidase-catalyzed one previously elaborated by the authors is that the former enzyme uses molecular oxygen instead of costly hydrogen peroxide (used by peroxidase) as an oxidant.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260607
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  • 62
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    A dynamic mathematical model for microbial removal of pyritic sulfur from coal (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 604-612 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A dynamic mathematical model has been developed to describe microbial desulfurization of coal by Thiobacillus ferrooxidans. The model considers adsorption and desorption of cells on coal particles and microbial oxidation of pyritic sulfur on particle surfaces. The influence of certain parameters, such as microbial growth rate constants, adsorption-descrption constants, pulp density, coal particle size, initial cell and solid phase substrate concentration on the maximum rate of pyritic sulfur removal, have been elucidated. The maximum rate of pyritic sulfur removal was strongly dependent upon the number of attached cells per coal particle. At sufficiently high initial cell concentrations, the surfaces of coal particles are nearly saturated by the cells and the maximum leaching rate is limited either by total external surface area of coal particles or by the concentration of pyritic sulfur in the coal phase. The maximum volumetric rate of pyritic sulfur removal (mg S/h cm3 mixture) increases with the pulp density of coal and reaches a saturation level at high pulp densities (e.g. 45%). The maximum rate also increases with decreasing particle diameter in a hyperbolic form. Increases in adsorption coefficient or decreases in the desorption coefficient also result in considerable improvements in this rate. The model can be applied to other systems consisting of suspended solid substrate particles in liquid medium with microbial oxidation occurring on the particle surfaces (e.g., bacterial ore leaching). The results obtained from this model are in good agreement with published experimental data on microbial desulfurization of coal and bacterial ore leaching.
    Additional Material: 12 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260608
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    Oxidative assimilation treatment of a nitrogen-deficient toxic waste (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 613-619 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Batch growth tests were performed under both replicating and nonproliferating (no nitrogen source in medium) conditions with acclimated heterogenous populations that utilized phenol as a sole source of carbon and energy. It was shown that the acclimated populations could efficiently remove the toxic waste component phenol under nonproliferating conditions by utilizing an oxidative assimilation mechanism. The phenol was assimilated and converted into nonnitrogenous storage products. During the assimilation process, the cells had a tendency to excrete some product (nonsubstrate) chemical oxygen demand (COD). Bench-scale oxidative assimilation units were operated by sequentially feeding a carbon source (phenol) and nitrogen source (ammonium sulfate) to heterogeneous populations. This demonstrated that, subsequent to the addition of the nitrogen source to the medium, the cells utilized the stored carbon for replication. Four of these units were operated at different phenol COD-to-ammonia-nitrogen ratios of 10:1, 20:1, 40:1, and 50:1. All of these units demonstrated excellent removal of phenol using an oxidative assimilation mechanism. These results suggested the feasibility of utilizing a continuous flow oxidative assimilation process for the treatment of nitrogen-deficient phenolic wastes. This process would be advantageous over conventional treatment processes in that it would realize a savings in chemical costs (ammonia as nitrogen source) and prevent leakage of excess ammonia from the system.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260609
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    Performance of biocatalysts with nonuniformly distributed immobilized enzyme (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 623-626 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260611
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  • 65
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    High-efficiency ethanol production from lignocellulosic residues pretreated with alkaline H2O2The mention of firm names of trade products does not imply that they are endorsed or recommended by the United States Department of Agriculture over other firms or similar products not mentioned. (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 628-631 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260613
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  • 66
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    Tyrosine hydroxylase activity of immobilized tyrosinase on enzacryl-AA and CPG-AA supports: Stabilization and properties (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1306-1312 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Frog epidermis tyrosinase has been immobilized on Enzacryl-AA (a polyacrylamide-based support) and CPGzirclad-Arylamine (a controlled pore glass support) in order to stabilize the tyrosine hydroxylase activity of the enzyme; in this way, the immobilized enzyme could be used to synthesize L-dopa from L-tyrosine. The activity immobilization yield YIMEact (higher than 86%), coupling efficiency (up to 90%), storage stability (no loss in 120 days), and reaction stability (t1/2 was higher than 20 h in column reactors) were measured for tyrosinase after its immobilization. The results showed a noticeable improvement (in immobilization yield, coupling efficiency, and storage and operational stabilities) over previous reports in which tyrosinase was immobilized for L-dopa production. The activity and stability of immobilized enzyme preparations working in three different reactor types have been compared when used in equivalent conditions with respect to a new proposed parameter of the reactor (Rp), which allows different reactor configurations to be related to the productivity of the reactor during its useful life time. The characteristic reaction inactivation which soluble tyrosinase shows after a short reaction time has been avoided by immobilization, and the stabilization was enhanced by the presence of ascorbate. However, another inactivation process appeared after a prolonged use of the immobilized enzyme. The effects of reactor type and operating conditions on immobilized enzyme activity and stability are discussed.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260261107
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  • 67
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    Covalent immobilization of FAD and glucose oxidase on carbon electrodes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1066-1070 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effectiveness of attaching flavin adenine dinucleotide (FAD) via a C bridge to Teflon-bonded carbon black (CB), and the subsequent immobilization of glucose oxidase on the FAD-modified electrodes has been studied by cyclic voltammetry. When FAD alone is bound to the electrode, it undergoes reduction and oxidation at -0.62 and -0.5 V, respectively - values similar to those obtained with free FAD. Compared to the free enzyme, the reduction of FAD as part of the immobilized enzyme is 200 mV more cathodic, while the oxidation potential remains the same in both cases.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260908
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  • 68
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    Bioengineering of photosynthetic membranes. Requirement of magnesium for the conversion of chlorophyllide a to chlorophyll a during the greening of etiochloroplasts in vitro (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 481-487 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The massive conversion of δ-aminolevulinic acid (ALA) to protochlorophyllide (Pchlide) and the massive conversion of chlorophyllide a (Chlide a) to chlorophyll a (Chl a) are two essential conditions for the ALA-dependent assembly of photosynthetic membranes in vitro. In this work, we describe the development of a cell-free system capable of the forementioned biosynthetic activities at rates higher than in vivo, for the first 2 h of dark-incubation. The cell-free system consisted of (1) etiochloroplasts prepared from kinetin and gibberellic-acid-pretreated cucumber cotyledons, and (2) cofactors and additives described elsewhere and which are needed for the massive conversion of ALA to Pchlide, (3) high concentrations of ATP, MgCl2, and an isoprenol alcohol such as phytol, were required for the massive conversion of Chlide a to Chl a. An absolute and novel requirement of Mg2+ for the conversion of Chlide a to Chl a was also demonstrated. In addition to the role of phytol as a substrate for the conversion of Chlide a to Chl a, the data suggested that this alcohol may also be involved in the regulation of the reactions between ALA and Pchlide. It is proposed that during greening, the conversion of Chlide a to Chl a may follow different biosynthetic rates, having different substrate and cofactor requirements, depending on the stage of plastid development.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260512
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  • 69
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    The growth dynamics of a methanol-utilizing bacterium L3 in a batch bioreactor (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1352-1363 
    Details
    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 dynamics of a methanol utilizing bacterium, L3, in batch bioreactors were experimentally investigated. Formaldehyde, a key intermediate of methanol oxidation, is indicated to have a significant role in the complex batch growth behavior of L3. The intricate batch growth dynamics of many microorganisms can be elegantly characterized by examining the specific rates of exchange of nutrients and products between the cells and the cellular environment. Following such an analysis, the batch growth of L3 on methanol was characterized by the presence of unbalanced and balanced growth phases. The nature and significance of nutrient and product concentration profiles or semilog-arithmic profiles of nutrient and product exchange rates during balanced and unbalanced growth phases are also outlined.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260261113
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    A modified matrix perfusion-microcarrier bead cell culture system. II. Production of human (β) interferon in a matrix perfusion system (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 508-512 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Addition of microcarrier beads to a matrix perfusion cell culture system allowed growth of anchorage dependent human foreskin fibroblasts which would not grow in the culture units alone. The utility of the system for collection of cellular products was demonstrated by the induction and harvesting of human (β) interferon. Interferon production was highest in perfusion cultures when medium was circulated throughout the induction and when inducer containing 100 μg/mL polyriboinosinic: polyribocytidylic acid was placed directly in contact with cells in the extracapillary space. These conditions provided 4-to-10-fold greater interferon yields per cell, and approximately 12-fold increases per vessel, than monolayer cultures. Perfusion grown cells produced interferon at a maximal level for 20 h postinduction compared to approximately 2 h for monolayer grown cells, thus giving a higher total yield of interferon. Other procedures increasing the efficiency of the system included priming with 50 U/mL interferon standard, reinduction of cells, use of antibiotic free medium, reduced serum concentrations, and in vitro aging of the cells.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260516
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  • 71
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    Effect of modifying agents on immobilized alcohol dehydrogenase (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 544-545 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260521
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  • 72
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    Immobilization of enzyme on nylon containing pendant quaternized amine groups (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1390-1392 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260261117
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  • 73
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    Viable microorganism detection by induced fluorescence (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1395-1397 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260261119
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  • 74
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    Preparation of immobilized glucomylase using ca-alginate gel coated with partially quaterized poly(ethleneimine) (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1393-1394 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260261118
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  • 75
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    Double-substrate-limited growth of escherichia coli (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1398-1401 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261120
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  • 76
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    Two-phase anaerobic fermentation of liquid swine waste to methane (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1425-1429 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two-phase anaerobic digestion of liquid swine manure has been developed with options for single-cell protein (SCP) or methane production. In the acidogenic phase at two to four days retention time, and 2.5-7.0% dry matter (DM) concentration, 8-46% of the volatile solids was solubilized. Maximum reactor capacity was 3.86 g/L at 7.0% DM concentration, but optimal operation was achieved at 4.5% DM concentration at four days retention time. The second methanogenic phase was operated continuously and had a maximum specific methane production rate of 0.70 L/L day at 12 days retention time. With recirculation, the rate was 1.16 L/L day at 8.5 days retention time with 52.7% conversion of organic matter. Maximum digestibility was 66% of the lignin free organic matter.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261205
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  • 77
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    The impulse response of Chlamydomonas reinhardii in nitrite-limited chemostat culture (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1430-1435 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article presents a clear experimental determination of the behavior of nutrient uptake rate, mean cell nutrient content, and specific growth rate following the injection of pulses of additional limiting nutrient into a chemostat culture of Chlamydomonas reinhardii. The uptake rate per cell is a hyperbolic function of external nutrient concentration. The specific growth rate is related to the mean cell nutrient content by a hysteresis loop. The data obtained is used to test the performance of the Caperon-Droop mean cell quota model. It is demonstrated that this model cannot be used under severe transient conditions, even when modified by the introduction of a discrete time delay, a simple memory function, or time-dependent intracellular nutrient processing.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261206
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  • 78
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    Estimation of yield, maintenance, and product formation kinetic parameters in anaerobic fermentations (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1436-1444 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In many anaerobic fermentation processes, high energy bonds in adenosine triphosphate (ATP) are produced when available electrons are converted from organic substrate into extracellular organic products such as ethanol. The true growth yield and maintenance parameters are directly related to the product formation kinetic parameters for these anaerobic processes. Methods are presented which allow all of the experimental measurements to be used simultaneously to estimate these parameters. Results are presented for several different anaerobic fermentations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261207
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  • 79
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    Comparison of different strategies for the lipase-catalyzed preparative resolution of racemic acids and alcohols: Asymmetric hydrolysis, esterification, and transesterification (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1449-1454 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Lipase from Candida cylindracea has been found to be a highly stereospecific catalyst suitable for preparative resolution of racemic acids and alcohols. Using (R, S)-2-(p-chlorophenoxy) propionic acid (whose R isomer is a herbicide) and (R, S)-sec-butanol (a versatile synthon) as model compounds, three alternative approaches to lipase-catalyzed resolutions - asymmetric hydrolysis, esterification, and transesterification - have been compared. Enzymatic esterification in biphasic systems has been ruled out for preparative resolutions because addition of the acids lowers the pH of the aqueous phase thereby greatly reducing the efficiency of the procedure. Both enzymatic hydrolysis and biphasic transesterification afforded resolution of the racemates on a gram scale. From the standpoint of productivity, ease of product separation, and the amount of steps required, lipasecatalyzed asymmetric hydrolysis has been judged to be superior for the practical resolution of racemic acids, and lipase-catalyzed asymmetric transesterification to be the method of choice for the practical resolution of racemic alcohols.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261209
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  • 80
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    Kinetics of enzymatic starch liquefaction: Simulation of the high-molecular-weight product distribution (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1475-1484 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Enzymatic corn starch liquefaction with α-amylase was carried out. Molecular weight distributions of the resulting hydrolysates are presented using aqueous size exclusion chromatographic techniques. It is demonstrated that despite the fact that the enzyme employed reacts in a random endoacting manner, the product distributions are nonrandom. The results are explained in part by a multimerization process whereby the polymeric substrate molecules preferentially associate, forming intermolecular aggregates. These aggregates are either a consequence of the manner in which the material is deposited into the native granular structure of starch or due to intrinsic physical chemical properties of the polysaccharide. In the latter case, the results are shown to correspond to known multimerized amylose, although complete characterization of the polysaccharide is currently not available. The results presented are used to develop a simplified kinetic model of starch liquefaction and shown to simulate the product distributions accurately.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260261212
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  • 81
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    Optimization of a reactor assembly for the production of 6-APA from penicillin-VPaper was presented at CCRE-8 (Colloquium on Chemical Reaction Engineering), Copenhagen, Denmark, September 8-9, 1983. (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1485-1491 
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    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The design and operation of an industrial penicillin-V deacylation reactor is simulated, using a kinetic expression and mass transport parameters for the immobilized enzyme particles which were determined experimentally in a previous study. It is desirable to use a series of equalsized plug flow reactors with pH control at the entrance to each reactor, and with a possibility of recycling reactant in each reactor. These measures are necessary to avoid a steep pH profile through the reactor; the deacylation reaction is accompanied by an increase of acidity of the reaction medium, and H+ is a strong inhibitor and may deactivate the enzyme. The optimization study which is carried out at a fixed penicillin conversion of x = 0.99 shows that it is uneconomical to use penicillin feed concentrations above 150mM-175mM, and that the buffer concentration in the reaction medium should not be less than 50mM-75mM. Increasing the number of reactors from 4 to 8 or 10 leads to higher productivity of 6-APA, and a moderate recycle in the first couple of reactors diminishes the sharp decrease in pH which will be found in a straight plug flow reactor operation of the equipment. Higher pumping costs and lower productivity are unavoidable drawbacks of an operation mode where the separation costs for the product mixture are desired to be low.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260261213
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    A comparative study of the enzymatic hydrolysis of acid-pretreated white pine and mixed hardwood (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1498-1505 
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    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Removal of hemicellulose by acid pretreatment in a flow reactor followed by enzymatic hydrolysis of the neutralized slurry has resulted in glucose yields as high as 95% for mixed hardwood. For white pine, however, the maximum glucose yield is 65%. Although pine has a higher extractives content, removal of the extractives prior to enzymatic hydrolysis does not increases the glucose yield. Pore size measurements reveal that the increase in pore volume, in the size range of the cellulase molecule, following pretreatment for pine is only about one-half the value obtained with mixed hardwood. This suggests that pore volume is an important determinant of substrate-enzyme reactivity.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260261215
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  • 83
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    Computer model for glucose-limited growth of a single cell of Escherichia coli B/r-A (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 1140-1140 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260925
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  • 84
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    The effect of organosolv pretreatment on the enzymatic hydrolysis of poplar (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 670-676 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The use of alcohol/water/catalyst mixtures to delignify wood allows the lignin to be recovered in a usable form while leaving the carbohydrate fraction relatively intact. The effects of temperature, reaction time, and the type of solvent and catalyst on the delignification of milled poplar wood were investigated. The lignin, cellulose, and hemicellulose composition of the pretreated material was measured for each treatment condition. In addition, the pretreated samples were subjected to enzymatic hydrolysis using the cellulases produced by the thermophilic bacterium Thermomonospora sp. YX. The extent of enzymatic hydrolysis was characterized using an empirical model, and the results were used to examine the effectiveness of the pretreatment.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260706
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    Study of models of single populations: Development of equations used in microorganism cultures (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 682-686 
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    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article derives a number of equations which can be used in both continuous and the semicontinuous cultures of microorganism populations in chemostat systems. Using these equations, some phenomena which have been known for many years can be explained reasonably in terms of chemical kinetics, and a number of analytical solutions can be obtained instead of numerical solutions previously published.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260708
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  • 86
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    Microbial oxidation of dibenzothiophene by the thermophilic organism Sulfolobus acidocaldarius (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 687-690 
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    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The refractory organic sulfur compound dibenzothiophene (DBT) has been oxidized by the thermophilic, sulfur oxidizing organism Sulfolobus acidocaldarius. Sulfate ions were released into the medium as the oxidation product. The kinetics of this oxidation have been investigated on the basis of sulfate released as a result of oxidation. Dibenzothiophene was found to be inhibitory to the organisms for initial concentrations over 500 mg/L. The organism may prove to be capable of oxidizing thiophene compounds present in oil refinery wastewater, coal, and crude oil.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/bit.260260709
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    Utilization of light for the assimilation of organic matter in Chlorella sp. VJ79 (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 677-681 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Chlorella sp. strain VJ79 was isolated from a total heterotrophic count of a wastewater collector. It grows autotrophically, heterotrophically, and mixotrophically on a variety of organic substrates. Glucose and serine promote a mixotrophic growth from which the yield is higher than the sum of autotrophic and heterotrophic yields, but serine assimilation requires light. The interaction of glucose and light was studied in proliferating and nonproliferating cells by respirometry (IRGA and Warburg) and growth experiments. Glucose inhibits the photosynthetic CO2 fixation ten-fold and modifies the pigmentary system as it does in heterotrophic cultures. Light inhibits glucose uptake and assimilation, but under mixotrophic conditions maximal utilization of glucose is obtained. Mutants defective in autotrophic growth were isolated by mutagenesis with nitrosoguanidine. They show a degenerated pigmentary system and a mixotrophic growth yield equal to that of the heterotrophic growth. The analysis of the mixotrophic system shows that light energy, dissipated during autotrophic growth, is used under mixotrophic conditions. From the increase in growth, the increase in photosynthetic efficiency can be calculated as ca. sixfold.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260707
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  • 88
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    Electronic Resource
    Mechanisms for the acoustic conditioning of protein precipitates to improve their separation by centrifugation (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 691-698 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A theoretical description of a low-frequency, dual-source acoustic treatment of protein precipitates is presented. Two mechanisms for the potential improvement of the centrifugal separation of precipitates are proposed. They are acoustic aggregation, which causes an increase in particle size, and aggregate deformation, which results in an increase in aggregate density. Experiments with isoelectric soya protein precipitate indicated that the extent of ageing prior to acoustic conditioning is important. Support for both aggregation and dewatering was found and a maximum increases in the particle settling velocity of 20% was observed.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260710
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  • 89
    Electronic Resource
    Electronic Resource
    Effect of melanin on enzymatic hydrolysis of cellulosic waste (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 699-701 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Wood waste powder from Tectona grandis containing melanin was less susceptible to enzymatic hydrolysis than powder without melanin. About a 53% increase in saccharification was noted when melanin was removed. Melanin caused inhibition to all cellulolytic enzymes, but in different degrees. Endo-β-1,4-glucanase and β-glucosidase were markedly inhibited when melanin was preincubated with enzyme, while exo-β-1,4-glucanase was severely inhibited when melanin was preincubated with substrate. The latter was found to be dependent on the contact time. The activities of endo-β-1,4-glucanase and β-glucosidase were noncompetitively inhibited by melanin.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260711
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  • 90
    Electronic Resource
    Electronic Resource
    Enzymic saccharification of sugar beet pulp (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 714-718 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Culture filtrates of Talaromyces emersonii UCG 208 grown on beet pulp can convert the polysaccharide components of this agricultural waste to soluble sugars. The saccharification process is facilitated if the pulp is milled or incubated with alkali or peracetic acid before addition of enzyme. However, treatment of unmilled pulp with commercial pectinase prior to incubation with Talaromyces filtrate is also very effective; under suitable conditions, complete hydrolysis of total polysaccharides has been achieved.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260713
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  • 91
    Electronic Resource
    Electronic Resource
    Mechanical control of foaming in a bubble column (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 702-713 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This study was performed to evaluate the effects of the air sparge rate, working liquid volume, liquid feed rate onto the disk, and disk diameter on the foam-breaking performance of foam-breaking apparatus with a rotating disk (FARD) installed in the bubble column. Experimental results showed that the smaller the air sparge rate and working liquid volume were, and the larger the liquid feed rate and disk diameter, the lower the critical disk rotational speed required for reduced foam-breaking. The presence of the effective ranges of the disk diameter and liquid feed rate for foam breaking was also confirmed. Furthermore, the quantitative predictions of the upper limits of the liquid feed rate, foam-breaking regions, and the required foam-breaking power were carried out, based on the results obtained above. Comparison of the FARD with two conventional mechanical foam-breaking spray-type apparati also demonstrated the highest level of the FARD in respect not only to foam-breaking performance but also to power requirements.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260712
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  • 92
    Electronic Resource
    Electronic Resource
    The influence of fluid mixing upon respiratory patterns for extended growth of a methylotroph in an air-lift fermenter (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 719-726 
    Details
    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 methanol dispersion and fluid mixing upon respiratory patterns observed during unlimited fedbatch growth of the methylotrophic bacterium Methylophilus methylotrophus has been investigated. A concentric tube air-lift fermenter was employed for which the mixing and fluid circulation patterns have been well characterized. Respiratory quotients showed a marked dependence upon the position in the vessel at which methanol was injected, the volumetric rate of such methanol addition, the fluid circulation time, and the local mixing behavior; the latter two factors of which are both determined by the air throughput. Such variations are discussed on the basis of simple mixing concepts and observations of fluid dispersion.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260714
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  • 93
    Electronic Resource
    Electronic Resource
    Improved biocatalyst effectiveness by controlled immobilization of enzymes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 727-736 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Nonuniform enzyme distributions can be obtained by kinetic control of the immobilization process. Such heterogeneous biocatalysts exhibit higher effectiveness compared to conventional immobilization procedures, when the mass transfer of substrates or products is limiting. Model calculations provide some insight into the relative weight of the immobilization parameters with respect to optimal control of the enzyme distribution. Experimental results and model calculations show that considerably improved effectiveness of biocatalysts can be obtained. The role of external mass transfer is emphasized.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260715
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  • 94
    Electronic Resource
    Electronic Resource
    Use of catalase from Escherichia coli in model experiments for oxygen supply of microorganisms with hydrogen peroxide (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 737-741 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A catalase has been purified from aerobically grown Escherichia coli K12. The enzyme exhibits unorthodox properties compared with catalyse from bovine liver and seems to be identical to hydroperoxidase II from E. coli. A mathematical model is presented which makes it possible to calculate the steady-state concentration of hydrogen peroxide in an open system. The model has been verified experimentally. It has been shown that the catalase from E. coli is better suited than the bovine liver enzyme for oxygen supply to cell suspensions using hydrogen peroxide.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260716
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  • 95
    Electronic Resource
    Electronic Resource
    Ethanol fermentation in a continuous tower fermentor (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 742-747 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mutant of Saccharomyces cerevisiae, which forms large, multicellular flocs in liquid culture, rapidly fermented media containing high concentrations of glucose (100-180 g/L) in a continuous nonaerated tower fermentor at 30°C. The fermentor operated continuously for seven months. Batch and tower fermentor data were fitted to a kinetic model incorporating linear ethanol inhibition and Monod dependence on glucose. Conversion, ethanol yield, and ethanol productivity were related to the apparent fermentation time for initial glucose concentrations of 130 and 180 g/L. Productivities of 8-12 g ethanol/L h were achieved through the yeast bed giving conversions exceeding 90% of the theoretical yield.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260717
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  • 96
    Electronic Resource
    Electronic Resource
    Continuous growth kinetics of Candida utilis in pineapple cannery effluent (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 748-752 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Candida utilis was grown on a pineapple cannery effluent as the sole carbon and energy source in a chemostat at dilution rates between 0.10 and 0.62 h-1 to determine the growth kinetics. The principal sugars in the effluent were sucrose, glucose, and fructose. The cell yield coefficient on carbohydrate varied with dilution rate and a maximum value of 0.63 was observed at a dilution rate of 0.33 h-1. The steady-state concentrations of carbohydrate, reducing sugar, and chemical oxygen demand (COD) appeared to follow Monod saturation kinetics with increasing dilution rate, although none of the measured parameters represented a pure substrate. The maximum specific growth rate and reducing sugar saturation constant were 0.64 h-1 and 0.060 g/L, respectively. A maximum cell mass productivity of 2.3 g/L h was observed at a dilution rate of 0.51 h-1. At this dilution rate, only 68% of the COD was removed. A 95% COD removal was attained at a dilution rate of 0.10 h-1. Optimal yeast productivity and COD reduction occurred at a dilution rate of 0.33 h-1.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260718
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  • 97
    Electronic Resource
    Electronic Resource
    Degradation of a washed carrot preparation by cellulases and pectinases (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 788-796 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A washed carrot substrate, prepared with high yields and easy handling properties, was found to be a suitable substrate for studying cellulolytic and pectinolytic degradation processes. A cellulase from Trichoderma reesei, and Rohament P, a macerating enzyme from Aspergillus alleaceǔs in endopolygalacturonase, degraded the washed carrot substrate to an extent of 60%. With the combined action of both enzymes, degradation was more than 80%. Simultaneous action of both enzymes was more efficient than their sequential use. The effect of temperature, pH, incubation time, enzyme concentration, and substrate concentration on the degradation by the single enzymes and their mixture were studied. Gas chromatographic sugar analysis revealed that Rohament P liberated glucose, arabinose, and galactose in the low-molecular-weight fraction obtained by ultrafiltration, in addition to high amounts of galacturonic acid. These carbohydrates were also found in the high-molecular-weight fraction (retentate) together with rhamnose and mannose. Cellulase BC released mainly glucose, although galacturonic acid, arabinose, xylose, and mannose were also detected both in the ultrafiltrate and retentate. Morphologically, during Rohament P degradation of the washed carrot substrate, damaged tissues and disintegrated cells were seen, whereas on cellulase BC action mainly disintegrated cell walls were observed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260725
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  • 98
    Electronic Resource
    Electronic Resource
    The effects of browning reaction on the yeast (S. cerevisiae) fermentation (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 797-799 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260726
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  • 99
    Electronic Resource
    Electronic Resource
    Limitations of the DNS assay for reducing sugars from saccharified lignocellulosics (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 800-802 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260727
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  • 100
    Electronic Resource
    Electronic Resource
    Sampling thick mycelial suspensions from an air-lift fermenter (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 803-804 
    Details
    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
    URL: http://dx.doi.org/10.1002/bit.260260728
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