ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Biogenesis and turnover of peroxisomes involved in the concurrent oxidation of methanol and methylamine in Hansenula polymorpha (1981)
    Springer
    Archives of microbiology 129 (1981), S. 35-41 
    Details
    ISSN: 1432-072X
    Keywords: Peroxisome ; Methanol ; Methylamine ; Yeast ; Hansenula polymorpha ; Alcohol oxidase ; Amino oxidase ; Catalase ; Catabolite inactivation ; Turnover ; Cytochemical localization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth of Hansenula polymorpha in shake flasks and chemostat cultures in the presence of methanol as the sole source of carbon and methylamine as the sole source of nitrogen was associated with the development of peroxisomes in the cells. The organelles were involved in the concurrent oxidation of these two compounds, since they contained both alcohol oxidase and amine oxidase, which are key enzymes in methanol and methylamine metabolism, respectively. In addition catalase was present. Peroxisomes with a completely crystalline substructure were observed in methanol-limited chemostat-grown cells. Amine oxidase probably formed an integral part of these crystalloids, whereas catalase was present in a freely diffusable form. Transfer of cells, grown in a methanol-limited chemostat in the presence of methylamine into glucose/ammonium sulphate media resulted in the loss of both alcohol oxidase and amine oxidase activity from the cells. This process was associated with degradation of the crystalline peroxisomes. However, when cells were transferred into glucose/methylamine media, amine oxidase activity only declined during 2 h after the transfer and thereafter increased again. This subsequent rise in amine oxidase activity was associated with the development of new peroxisomes in the cells in which degradation of the crystalline peroxisomes, originally present, continued. These newly formed organelles probably originated from peroxisomes which had not been affected by degradation. When in the methanollimited chemostat methylamine was replaced by ammonium sulphate, repression of the synthesis of amine oxidase was observed. However, inactivation of this enzyme or degradation of peroxisomes was not detected. The decrease of amine oxidase activity in the culture was accounted for by dilution of enzyme as a result of growth and washout.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417176
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Arthrobacter P 1, a fast growing versatile methylotroph with amine oxidase as a key enzyme in the metabolism of methylated amines (1981)
    Springer
    Archives of microbiology 129 (1981), S. 72-80 
    Details
    ISSN: 1432-072X
    Keywords: Arthrobacter ; Facultative methylotroph ; Amine oxidase ; Catalase ; RuMP cycle of formaldehyde fixation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A facultative methylotrophic bacterium was isolated from enrichment cultures containing methylamine as the sole carbon source. It was tentatively identified as an Arthrobacter species. Extracts of cells grown on methylamine or ethylamine contained high levels of amine oxidase (E.C. 1.4.3.) activity. Glucose- or choline-grown cells lacked this enzyme. Oxidation of primary amines by the enzyme resulted in the formation of H2O2; as a consequence high levels of catalase were present in methylamine-and ethylamine-grown cells. The significance of catalase in vivo was demonstrated by addition of 20 mM aminotriazole (a catalase inhibitor) to exponentially growing cells. This completely blocked growth on methylamine whereas growth on glucose was hardly affected. Cytochemical studies showed that methylamine-dependent H2O2 production mainly occurred on invaginations of the cytoplasmic membrane. Assimilation of formaldehyde which is generated during methylamine oxidation was by the FBP variant of the RuMP cycle of formaldehyde fixation. The absence of NAD-dependent formaldehyde and formate dehydrogenases indicated the operation of a non-linear oxidation sequence for formal-dehyde via hexulose phosphate synthase. Enzyme profiles of the organism grown on various substrates suggested that the synthesis of amine oxidase, catalase and the enzymes of the RuMP cycle is not under coordinate control.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417184
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cytochemical localization of catalase activity in methanol-grown Hansenula polymorpha (1975)
    Springer
    Archives of microbiology 105 (1975), S. 261-267 
    Details
    ISSN: 1432-072X
    Keywords: Methanol ; Yeasts ; Microbodies ; Diaminobenzidine ; Catalase ; Methanol oxidase ; Hanseula polymorpha
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The localization of peroxidase activity in methanol-grown cells of the yeast Hansenula polymorpha has been studied by a method based on cytochemical staining with diaminobenzidine (DAB). The oxidation product of DAB occurred in microbodies, which characteristically develop during growth on methanol, and in the intracristate space of the mitochondria. The staining of microbodies was H2O2 dependent, appeared to be optimal at pH 10.5, diminished below pH 10 and was inhibited by 20 mM 3-amino 1,2,4 triazole (AT). In contrast to these observations, the reaction in the mitochondria was not H2O2 dependent and not notably affected by differences in pH in the range of 8.5 to 10.5. Microbodies and mitochondria were also stained when H2O2 was replaced by methanol. Appropriate control experiments indicated that in this case methanol oxidase generated the H2O2 for the peroxidative conversion of DAB by catalase. These results suggest that catalase is located in the microbodies of methanol-grown yeasts. A model for a possible physiological function of the microbodies during growth on methanol is put forward.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447145
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Cytochemical studies on the localization of methanol oxidase and other oxidases in peroxisomes of methanol-grown Hansenula polymorpha (1976)
    Springer
    Archives of microbiology 111 (1976), S. 123-135 
    Details
    ISSN: 1432-072X
    Keywords: Cytochemical localization ; Peroxisome ; Catalase ; Methanol oxidase ; d-Amino acid oxidase ; α-Hydroxyacid oxidase ; Methanol-assimilating yeast ; Hansenula polymorpha
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The localization of methanol oxidase activity in cells of methanol-limited chemostat cultures of the yeast Hansenula polymorpha has been studied with different cytochemical staining techniques. The methods were based on enzymatic or chemical trapping of the hydrogen peroxide produced by the enzyme during aerobic incubations of whole cells in methanol-containing media. The results showed that methanol-dependent hydrogen peroxide production in either fixed or unfixed cells exclusively occurred in peroxisomes, which characteristically develop during growth of this yeast on methanol. Apart from methanol oxidase and catalase, the typical peroxisomal enzymes d-aminoacid oxidase and l-α-hydroxyacid oxidase were also found to be located in the peroxisomes. Urate oxidase was not detected in these organelles. Phase-contrast microscopy of living cells revealed the occurrence of peroxisomes which were cubic of form. This unusual shape was also observed in thin sections examined by electron microscopy. The contents of the peroxisomes showed, after various fixation procedures, a completely crystalline or striated substructure. It is suggested that this substructure might represent the in vivo organization structure of the peroxisomal enzymes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446559
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Methanol metabolism in yeasts: Regulation of the synthesis of catabolic enzymes (1980)
    Springer
    Archives of microbiology 124 (1980), S. 115-121 
    Details
    ISSN: 1432-072X
    Keywords: Derepression ; Catabolite inactivation ; Alcohol oxidase ; Catalase ; Formaldehyde dehydrogenase ; Formate dehydrogenase ; Hansenula polymorpha ; Kloeckera sp. 2201 ; Peroxisomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The regulation of the synthesis of four dissimilatory enzymes involved in methanol metabolism, namely alcohol oxidase, formaldehyde dehydrogenase, formate dehydrogenase and catalase was investigated in the yeasts Hansenula polymorpha and Kloeckera sp. 2201. Enzyme profiles in cell-free extracts of the two organisms grown under glucose limitation at various dilution rates, suggested that the synthesis of these enzymes is controlled by derepression — represion rather than by induction — repression. Except for alcohol oxidase, the extent to which catabolite repression of the catabolic enzymes was relieved at low dilution rates was similar in both organisms. In Hansenula polymorpha the level of alcohol oxidase in the cells gradually increased with decreasing dilution rate, whilst in Kloeckera sp. 2201 derepression of alcohol oxidase synthesis was only observed at dilution rates below 0.10 h−1 and occurred to a much smaller extent than in Hansenula polymorpha. Derepression of alcohol oxidase and catalase in cells of Hansenula polymorpha was accompanied by synthesis of peroxisomes. Moreover, peroxisomes were degraded with a concurrent loss of alcohol oxidase and catalase activities when excess glucose was introduced into the culture. This process of catabolite inactivation of peroxisomal enzymes did not affect cytoplasmic formaldehyde dehydrogenase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427715
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Characterization of glyoxysomes in yeasts and their transformation into peroxisomes in response to changes in environmental conditions (1983)
    Springer
    Archives of microbiology 136 (1983), S. 28-38 
    Details
    ISSN: 1432-072X
    Keywords: Yeasts ; Candida utilis ; Hansenula polymorpha ; Microbodies ; Peroxisomes ; Glyoxysomes ; Cell fractionation ; Cytochemistry ; Catalase ; Glyoxylate cycle ; Oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During growth of the yeasts Candida utilis and Hansenula polymorpha in mineral media containing ethanol as a carbon source and ammonium sulphate as a nitrogen source, the specific activities of isocitrate lyase and malate synthase were significantly increased when compared to glucose/ammonium sulphate-grown cells. In addition to the enhanced levels of these glyoxylate cycle enzymes, an increase in the specific activities of d-amino acid oxidase, amine oxidase or urate oxidase was observed when ammonium sulphate in the ethanol medium was replaced by d-alanine, methyl- or ethylamine, or uric acid. The subcellular localization of these enzymes was investigated by cell fractionation studies involving homogenization of protoplasts followed by differential and sucrose gradient centrifugation. In ethanol/ammonium sulphate-grown cells, isocitrate lyase and malate synthase cosedimented in a fraction together with catalase and part of the malate dehydrogenase. Electron microscopy revealed that this fraction consisted of microbodies which must be regarded as glyoxysomes. Two other glyoxylate cycle enzymes, citrate synthase and aconitase together with the other part of malate dehydrogenase, cosedimented with cytochrome c oxidase, a mitochondrial marker enzyme. In ethanol/d-alanine-, ethanol/methylamine- or ethanol/ethylamine-grown C. utilis and ethanol/uric acid-grown H. polymorpha, a peroxisomal enzyme, i.e. d-amino acid oxidase, amine oxidase or uric acid oxidase cosedimented with the glyoxysomal key enzymes. Cytochemical staining experiments demonstrated that in these variously-grown cells the activities of the oxidases were confined to the microbodymatrix; this also contained malate synthase activity. Transfer of C. utilis cells from glucose/ammonium sulphate- into ethanol/ammonium sulphate-containing media resulted in an increase in the original size and volume fraction of the microbodies. A further increase was observed when ammonium sulphate was replaced by methylamine. Essentially similar results were obtained with H. polymorpha cells. In neither of the two organisms indications of de novo synthesis of microbodies was obtained during transfer experiments. Invariably the microbodies developing in cells placed in the new environment originated from organelles already present in the inoculum cells by import of the substratespecific enzyme protein(s). The combined results of biochemical, cytochemical and electron microscopical experiments showed that in the yeasts studied under appropriate conditions glyoxysomal and peroxisomal enzyme activities were localized in one and the same microbody, rather than in separate organelles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00415606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Peroxisomes in intestinal and gallbladder epithelial cells of the stickleback, Gasterosteus aculeatus L. (Teleostei) (1988)
    Springer
    Cell & tissue research 251 (1988), S. 685-689 
    Details
    ISSN: 1432-0878
    Keywords: Peroxisomes ; D-amino acid oxidase ; Catalase ; Cytochemistry ; Intestinal epithelium ; Gallbladder epithelium ; Gasterosteus aculeatus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The occurrence of microbodies in the epithelial cells of the intestine and gallbladder of the stickleback, Gasterosteus aculeatus L., is described. In the intestine the organelles are predominantly located in the apical and perinuclear zone of the cells and may contain small crystalline cores. In gallbladder epithelial cells the microbodies are distributed randomly. The latter organelles are characterized by the presence of large crystalloids. Cytochemical and biochemical experiments show that catalase and D-amino acid oxidase are main matrix components of the microbodies in both the intestinal and gallbladder epithelia. These organelles therefore are considered peroxisomes. In addition, in intestinal mucosa but not in gallbladder epithelium a low activity of palmitoyl CoA oxidase was detected biochemically. Urate oxidase and L-α hydroxy acid oxidase activities could not be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...