Library

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
    Isolation and characterization of a bacterium possessing L-phenylalanine dehydrogenase activity (1984)
    Springer
    Archives of microbiology 137 (1984), S. 47-52 
    Details
    ISSN: 1432-072X
    Keywords: Phenylalanine dehydrogenase ; NAD+-dependence ; Reductive aminoation ; Brevibacterium spec. ; Selective enrichment with L-phenylalanine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The new enzyme phenylalanine dehydrogenase [L-phenylalanine: NAD+-oxidoreductase (deaminating)] was detected in the crude extract of a strain of Brevibacterium spec. The bacterium was isolated from a soil sample by enrichment with phenylalanine. This strain was the only one containing phenylalanine dehydrogenase out of 173 tested strains, among them 22 of the genus Brevibacterium, 74 strains from soil samples and 77 strains from a culture collection belonging to several genera. The enzyme is involved in the degradation of phenylalanine and could be induced by addition of L-, D-, D,l-phenylalanine or L-histidine, the optimum inducer concentration of phenylalanine being 1%. The reaction mechanism of a reductive amination was confirmed by demonstrating the close coupling between NADH-consumption and phenylalanine production; ammonia could not be replaced by L-glutamate or L-aspartate as amino donor. The α-keto acid of L-tyrosine was converted too, while the corresponding compound of histidine was inactive. The optimum pH value for reductive amination in the crude extract was 8.5 and for oxidative desamination 10.5.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425806
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Engineering Aspects of Enzyme (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 613 (1990), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1990.tb18157.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Application of Sucrose Synthase from Rice Grains for the Synthesis of Carbohydrates (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 750 (1995), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1995.tb19975.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    TECHNICAL ASPECTS OF EXTRACTIVE ENZYME PURIFICATION (1981)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 369 (1981), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1981.tb14201.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Cell/adsorbent interactions in expanded bed adsorption of proteins (1999)
    Springer
    Bioseparation 8 (1999), S. 99-109 
    Details
    ISSN: 1573-8272
    Keywords: expanded bed adsorption ; fluidisation ; initial recovery ; protein purification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Expanded bed adsorption (EBA) is an integrated technology for the primary recovery of proteins from unclarified feedstock. A method is presented which allows a qualitative and quantitative understanding of the main mechanisms governing the interaction of biomass with fluidised resins. A pulse response technique was used to determine the adsorption of various cell types (yeast, Gram positive and Gram negative bacteria, mammalian cells and yeast homogenate) to a range of commercially available matrices for EBA. Cells and cell debris were found to interact with the ligands of agarose based resins mainly by electrostatic forces. From the adsorbents investigated the anion exchange matrix showed the most severe interactions, while cation exchange and affinity adsorbents appeared to be less affected. Within the range of biologic systems under study E. coli cells had the lowest tendency of binding to all matrices while hybridoma cells attached to all the adsorbents except the protein A affinity matrix. The method presented may be employed for screening of suitable biomass/adsorbent combinations, which yield a robust and reliable initial capture step by expanded bed adsorption from unclarified feedstock.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008071731987
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    d-(-)-Mandelic acid dehydrogenase from Lactobacillus curvatus (1988)
    Springer
    Applied microbiology and biotechnology 28 (1988), S. 433-439 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Production, purification and characterization of the NAD(H)-dependent d-mandelate dehydrogenase from Lactobacillus curvatus was studied. An enzyme level of about 150 U/1 could be obtained by anaerobic cultivation in liquid broth. The specific enzyme activity in the crude extract was 1—3 U/mg. Purification by liquidliquid extraction and ion exchange chromatography led to a preparation of 2100 U/mg. The molecular weight of the enzyme was determined to be 60000 (gel filtration on Superose S12) containing two subunits of 30000. A variety of aliphatic and aromatic α-keto acids are accepted as substrates by the mandelate dehydrogenase, for the substrate benzoylformate a Michaelis constant of 2·10-4M was measured. Cu2+-ions and mercury compounds such as HgCl2 or p-chloromercuribenzoate are strong inhibitors at concentrations of 0.1 mM. An unoptimized continuous conversion in an enzyme-membrane-reactor demonstrated that the enzyme could be applied for the stereospecific synthesis of d-mandelic acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00268209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Large scale production of d-lactate dehydrogenase for the stereospecific reduction of pyruvate and phenylpyruvate (1983)
    Springer
    Applied microbiology and biotechnology 18 (1983), S. 75-85 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary To initiate studies of the stereospecific reduction of pyruvate and phenylpyruvate to the corresponding d-2-hydroxyacids a limited screening was carried out for microorganisms possessing a high NADH-dependet d-lactate dehydrogenase activity. Lactobacillus confusus was found to produce the desired dehydrogenase, which showed also relatively high activity towards phenylpyruvate, so this strain was selected for large scale production of the enzyme. A procedure for large scale purification of the enzyme starting with 24 kg wet cells is described including liquid-liquid extraction, ultrafiltration and chromatography on DEAE-cellulose, yielding a catalyst with specific activities of 216 U×mg−1 for pyruvate reduction and 15 U×mg−1 for phenyl-pyruvate reduction. A further tenfold purification can be achieved by affinity chromatography on Blue-Sepharose C-6B. Parameters which are important for industrial application of the enzyme were determined: substrate specifity, pH and temperature optimum, temperature stability, stability at different pH-values, and the storage stability of the enzyme in crude extracts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500828
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Screening for a novel enzyme hydrolysing l-carnitine amide (1994)
    Springer
    Applied microbiology and biotechnology 40 (1994), S. 599-605 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In an extended screening using d,l-carnitine amide as carbon or nitrogen source about 1300 strains were obtained by enrichment culture. Of these, 65 strains possessed carnitine amidase activities. A single strain was identified as containing an enzyme able to hydrolyse only l-carnitine amide and yield carnitine of high enantiomeric purity (≥97) when incubated with the racemic substrate. During the initial optimisation of the culture conditions the volume activity could be improved 6.7-fold whereas the specific activity increased 3.6-fold. The enzyme is inducible by l-carnitine amide and carnitine and to a lesser degree also by λ-butyrobetaine and dehydrocarnitine. As judged by the fatty acids and quinone composition the strain belongs into the α-subgroup of purple bacteria but has not yet been classified by the German Culture Collection into a known genus of bacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00173314
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Screening for a novel enzyme hydrolysing l-carnitine amide (1994)
    Springer
    Applied microbiology and biotechnology 40 (1994), S. 599-605 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract. In an extended screening using d,l-carnitine amide as carbon or nitrogen source about 1300 strains were obtained by enrichment culture. Of these, 65 strains possessed carnitine amidase activities. A single strain was identified as containing an enzyme able to hydrolyse only l-carnitine amide and yield carnitine of high enantiomeric purity (≥97) when incubated with the racemic substrate. During the initial optimisation of the culture conditions the volume activity could be improved 6.7-fold whereas the specific activity increased 3.6-fold. The enzyme is inducible by l-carnitine amide and carnitine and to a lesser degree also by γ-butyrobetaine and dehydrocarnitine. As judged by the fatty acids and quinone composition the strain belongs into the α-subgroup of purple bacteria but has not yet been classified by the German Culture Collection into a known genus of bacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530050035
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Leucine dehydrogenase from Bacillus sphaericus. Optimized production conditions and an efficient method for its large-scale purification (1981)
    Springer
    Applied microbiology and biotechnology 12 (1981), S. 22-27 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary To develop a large-scale isolation of leucine dehydrogenase (E.C. 1.4.1.9) as industrial catalyst we carried out a limited screening for microorganisms with high leucine dehydrogenase activity. Conditions for the growth and enzyme formation of Bacillus sphaericus (DSM 396) which proved to be the best enzyme producer were optimized. The highest yield in volume and specific activity were obtained using glucose and yeast-extract in the medium. The highest specific enzyme activity was found at the end of the exponential growth phase. Cultivation of Bacillus sphaericus under optimal conditions increased the yield to about 3 U mg−1. The heat stability of the enzyme was exploited to develop a simple large-scale purification. Together with an ultrafiltration step, the enzyme could be enriched 9fold in a short time. After further purification using DE-cellulose an enzyme preparation (25fold enriched) was obtained; suitable as a technical catalyst in amino acid production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508114
    Library Location Call Number Volume/Issue/Year 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...