Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1432-072X
    Keywords: Exoenzymes ; Lipid bodies ; Lysosomes ; Microbodies ; Spherosomes ; Woronin bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acid phosphatase was localized by light and electron microscopy in chains of vacuoles in hyphal tip cells of Whetzelinia sclerotiorum. The Enzyme was present in these vacuoles whether or not conditions favored extracellular acid phosphatase secretion. Apical vesicles, microbodies, woronin bodies, and lipid bodies did not contain acid phosphatase. The implications regarding terminology of organelles in filamentous fungi are discussed with special reference to the fungal spherosome concept.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-072X
    Keywords: Piptocephalis unispora ; Mucorales ; Kickxellaceae ; Electron microscopy ; Germination ; Spore swelling ; Sporangiospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Germination of the sporangiospore of Piptocephalis unispora Benjamin, observed by means of light and electron microscopy, involved the formation of a new inner wall which became continous with the inner layer of the wall of the germ tube. The outer wall layer of the germ tube was continous with the original inner wall layer of the dormant spore. Preliminary details of appressorium structure were noted. Nutritional experiments indicated that sporangiospores required external sources of utilisable nitrogen and carbon compounds for maximal swelling and germ tube production. Limited development occurred when either nutrient was supplied singly. Comparison of germination of the asexual spore with that in other Mucorales, especially the Kickxellaceae, has been made, and the merosporangial status in P. unispora discussed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-072X
    Keywords: Alanine dehydrogenase ; Anabaena cylindrica ; Heterocysts ; Nitrogen fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The l-alanine dehydrogenase (ADH) of Anabaena cylindrica has been purified 700-fold. It has a molecular weight of approximately 270000, has 6 sub-units, each of molecular weight approximately 43000, and shows activity both in the aminating and deaminating directions. The enzyme is NADH/NAD+ specific and oxaloacetate can partially substitute for pyruvate. The K m app for NAD+ is 14 μM and 60 μM at low and high NAD+ concentrations, respectively. The K m app for l-alanine is 0.4 mM, that for pyruvate is 0.11 mM, and that for oxaloacetate is 3.0 mM. The K m app for NH 4 + varies from 8–133 mM depending on the pH, being lowest at high pH levels (pH 8.7 or above). Alanine, serine and glycine inhibit ADH activity in the aminating direction. The enzyme is active both in heterocysts and vegetative cells and activity is higher in nitrogen-starved cultures than in N2-fixing cultures. The data suggest that although alanine is formed by the aminating activity of ADH, entry of newly fixed ammonia into organic combination does not occur primarily via ADH in N2-fixing cultures of A. cylindrica. Ammonia assimilation via ADH may be important in cultures with an excess of available nitrogen. The deaminating activity of the enzyme may be important under conditions of nitrogen-deficiency.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-072X
    Keywords: Anthranilate synthase ; Cell permeabilisation ; Indoleglycerolphosphate synthase ; Saccharomyces cerevisiae ; Tryptophan biosynthetic enzymes ; Tryptophan pool
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The free tryptophan pool and the levels of two enzymes of tryptophan biosynthesis (anthranilate synthase and indoleglycerolphosphate synthase) have been determined in a wild type strain of Saccharomyces cerevisiae and in mutants with altered regulatory properties. The tryptophan pool of wild type cells growing in minimal medium is 0.07 μmole per g dry weight. Addition of anthranilate, indole or tryptophan to the medium produces a fifteen- to forty-fold increase in tryptophan pool, but causes no repression of the biosynthetic enzymes. Inclusion of 5-methyltryptophan in the growth medium causes a reduction in growth rate and a derepression of the biosynthetic enzymes, and this is shown here not to be correlated with a decrease in the free tryptophan pool. Mutants with an altered anthranilate synthase showing decreased sensitivity to inhibition by l-tryptophan or by the analogue dl-5-methyltryptophan have a tryptophan pool far higher than the wild type strain, but no repression of indoleglycerolphosphate synthase was observed. Mutants with an anthranilate synthase more sensitive to tryptophan inhibition show a slightly reduced tryptophan pool, but no derepression of indoleglycerolphosphate synthase was found. A mutant with constitutively derepressed levels of the biosynthetic enzymes shows a considerably increased tryptophan pool. Addition of 5-methyltryptophan to the growth medium of non-derepressible mutants causes a decrease in growth rate accompanied by a decrease in the tryptophan pool.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-072X
    Keywords: Amino acid analogs ; Feedback insensitive mutants ; Pseudomonas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mutants resistant to various combinations of threonine, lysine and/or their analogs were obtained and characterized in Pseudomonas acidovorans. In particular, mutants resistant to aminoethylcysteine had a dihydrodipicolinate synthetase insensitive to lysine inhibition whereas mutants resistant to threonine plus a low concentration of aminoethylcysteine had a feedback-insensitive aspartokinase.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 107 (1976), S. 205-206 
    ISSN: 1432-072X
    Keywords: Torulopsis ; Yeast ; New species ; Beer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new species of the genus Torulopsis has been isolated from several different samples of German Pilsener Beer. A description of the new species is given.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-072X
    Keywords: Thermophilic fungi ; Nomenclature ; Thielavia Zopf ; Chrysosporium Corda
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thielavia heterothallica spec. nov. is described as a heterothallic, thermophilic fungus with spherical, black, non-ostiolatecleistothecia; ellipsoidal, evanescent asci which contain eight one-celled ellipsoidal ascospores, darkening to deep brown to black, with one germ pore. The conidial state is Chrysosporium thermophilum (Apinis) von Klopotek.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-072X
    Keywords: Yeast mitochondria ; Cytochrome c peroxidase ; Catalase ; Peroxisomes ; Petite mutation ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cytochemical and ultrastructural analysis of wild-type cells of Saccharomyces cerevisiac, grown aerobically in a glucose-limited chemostat, shows that cytochrome c peroxidase is localized between the membranes of the cristae, that is, in the intracristal space. This enzyme is thus positioned appropriately within the organelle to act as an alternate terminal oxidase for the respiratory chain. The proximity of the peroxidase to major sites of generation of its two substrates may account for the small leakage of hydrogen peroxide from yeast mitochondria, as compared with the larger outflow from mammalian mitochondria. In the cytoplasmic petite mutant, gross distortion of promitochondrial membrane arrangement is evident. Nevertheless, cytochrome c peroxidase activity is present in the same amounts as is found in wildtype cell, and is localized predominantly within annuli of membrane which constitute the promitochondria in these cells. No unequivocal evidence was obtained for the localization of catalase in microbodies or other organelles in either wild-type or petite cells.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-072X
    Keywords: Thermophilic bacteria ; Obligate thermophile ; B. stearothermophilus ; Loss of viability ; Leakage of ribonucleoprotein ; Low temperatures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract One of the obligate thermophilic bacteria, Bacillus stearothermophilus, was unable to grow at temperatures below 35° C. About 80% of the population in the bacterial culture died at the temperatures, and the same extent of loss in either of the activities of oxygen consumption or synthesis of protein or nucleic acid of the organisms was observed. With the progress of death of the organisms, reduced nicotinamide-adenine dinucleotide came to be oxidized by the organisms, enzymes such as fructose-1,6-diphosphate aldolase, when the organisms were washed with phosphate buffer, were leaked out of the organisms, and an increasing amount of ribonucleoprotein was released into the culture medium. The change of the membrane state was then suggested to be one of the possible causes for the death of the organisms at the temperatures.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-072X
    Keywords: Schizophyllum commune ; Basidiospore germination ; Polyol dehydrogenases ; Polyacrylamide dise gel electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Enzymes of polyol metabolism were studied in basidiospore germination of Schizophyllum commune during periods of in vivo arabitol and mannitol pool depletion (growth on glucose-asparagine) and during their subsequent synthesis (growth on acetate-NH 4 + ). Optimal conditions for assays were established and specific activities of enzymes employing d-arabitol, d-mannitol, d-ribulose, d-fructose and d-xylulose as substrates were traced. Inquiries into the products formed during these reactions showed that d-ribulose generated arabitol while d-fructose produced mannitol with d-xylulose giving rise to xylitol. The dehydrogenase reactions were further investigated using polyacrylamide disc gel electrophoresis. Here was revealed the existence of at least two separate enzymatic activities pertaining to the catabolism of arabitol and mannitol. Also noted were the electrophoretic patterns when d-sorbitol, ribitol, xylitol and ethanol were used as substrates.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...