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
    Bidirectional measurement of hydrogenase activity by the pH-stat method
    Amsterdam : Elsevier
    Analytical Biochemistry 131 (1983), S. 525-529 
    Details
    ISSN: 0003-2697
    Keywords: Desulfovibrio hydrogenase ; hydrogen evolution ; hydrogenase assay ; immobilized hydrogenase activity ; pH-stat method
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0003-2697(83)90209-9
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Shear-induced structure in enzymatically-synthesized dextran solutions (1986)
    Springer
    Rheologica acta 25 (1986), S. 287-295 
    Details
    ISSN: 1435-1528
    Keywords: Dextran ; enzymatic synthesis ; shear flow ; stress growth ; structure formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract A number of dextran derivatives and low molecular weight dextrans have found outlets in different fields such as fine chemistry and pharmaceutical industry, whereas only a few native (high molecular weight) dextrans have found applications. Thus, theoretical studies have scarcely concerned the rheological properties of native dextran solutions. Among the different synthesis processes, only the enzymaticin vitro synthesis produces a pure dextran, thereby allowing the rheological behavior of dextran solutions to be interpreted in terms of molecular considerations. The shear viscosity curve reveals an irreversible threshold-type shear thickening at a specific critical shear rate $$\dot \gamma *$$ . The value of $$\dot \gamma *$$ depends on the temperature of experiments and on the dextran concentration. Transient experiments give a description of the shear-thickening as a function of time and allows us to study the effect of several parameters (temperature, solvents, etc.). The shear stress growth, during the structure formation, is made of two different kinetics: the first one depends strongly on the molecular conformation; the second one is the result of intermolecular interactions of the hydrogen-type bonds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01357955
    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 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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    On the production of dextran by free and immobilized dextransucrase (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 23 (1981), S. 2027-2037 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Dextransucrase from Leuconostoc mesenteroides was produced in a semicontinuous culture with slow addition of a concentrated sucrose solution. The resulting high activity of the fermentation broth allowed a one-step purification method, by gel permeation chromatography (GPC) in 96.4% yield. This procedure resulted in 140-fold purification, with specific activity of 122 U/mg. The enzyme was immobilized onto an amino-Spherosil support activated with glutaraldehyde. Preparations with dextransucrase activities as high as 40.5 U/g of support were obtained, when low specific area supports were used and maltose was added during the enzyme coupling. Diffusional limitations were found during enzyme reaction, as shown by a kinetic study. As a consequence of immobilization, the average molecular weight of dextrans seems to increase. Immobilized dextransucrase looks promising for low-molecular-weight dextran production. Clinical dextran was synthesized when the polysaccharides produced in the presence of maltose were used as acceptor of a second synthesis reaction. The molecular weight distribution of the resulting production was less disperse than when clinical dextran was produced by acid hydrolysis of high-molecular-weight dextran.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260230908
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Invertase covalent grafting onto corn stover (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 26 (1984), S. 658-664 
    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 covalent coupling of an invertase from baker's yeast onto an agricultural by-product, corn grits, has been developed. The optimal conditions for each step of the chemical modification of the support have been determined: oxidation with sodium metaperiodate, amination with ethylenediamine, reduction with sodium cyanoborohydride, and activation with glutaraldehyde. Activities up to 7.2 × 104 μmol reducing sugars produced/min g support could thus be achieved. Invertase coupling onto corn grits yields a derivative with a 25 times higher activity than when coupling this enzyme onto porous silica. The operational stability of invertase immobilized onto corn stover was found to be very high, with a half-life of up to 365 days at 40°C when using a 2M sucrose solution as substrate. This immobilization method could be easily scaled up to the preparation of 10 kg of invertase derivative.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260260704
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Influence of glucose on the kinetics of maltodextrin hydrolysis using free and immobilized glucoamylase (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 27 (1985), S. 1274-1275 
    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 study of the effect of glucose addition to the kinetics of maltodextrin hydrolysis catalyzed with free and immobilized Aspergillus niger glucoamylase does not show any significant glucose inhibitory effect. This result is in contradiction with data previously reported in the literature. On the contrary, a slight glucose-activating effect was observed. This effect was greater in the case of the immobilized enzyme. The glucose inhibitory effect may thus not be involved in the case of practical saccharification conditions catalyzed with glucoamylase when maltodextrins are used as substrate.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260270824
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Maltodextrin hydrolysis in a fluidized-bed immobilized enzyme reactor (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 151-159 
    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 present work deals with maltodextrin hydrolysis by glucoamylase immobilized onto corn stover in a fluidized bed reactor. An industrial enzyme preparation was covalently grafted onto corn stover, yielding an activity of up to 372 U/g and 1700 U/g for support particle sizes of 0.8 and 0.2 mm, respectively. A detailed kinetic study, using a differential reactor, allowed the characterization of the influence of mass transfer resistance on the reaction catalyzed by immobilized glucoamylase. A simple and general mathematical model was then developed to describe the experimental conversion data and found to be valid.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260280202
    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...