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The immobilized biocatalyst (IMB) is a key component of
biotransformation systems that are used to transform substrates to
desired products. The impro- ment of biocatalyst properties has a
direct influence on the overall effectiveness of the process based
on the biotransformation. The basic catalytic characte- stics of
biocatalyst that are followed include kinetic properties, pH
optima, stability,and inhibition. The investigation of catalytic
properties of immobilized enzymes is still a time consuming
procedure and is not always simple. In the 1980s,a major effort was
made to standardize the rules by which IMB is char- terized. The
Working Party of EFB on immobilized biocatalysts has formul- ed
principles of individual methods, among them the requirement of
kinetic characterization [1]. It was recommended to use a
packed-bed reactor,equipped with temperature control and with
infinite flow circulation. The system should be equipped with a
post-column unit to measure the time-dependence of the product or
substrate concentration [2, 3], the most commonly used analytical
methods being spectrophotometry, chemiluminiscence, automatic
titration, bioluminiscence, chromatography, polarimetry, and
biosensors based on the oxygen electrode. There are two main
drawbacks to the application of these methods: 1. The need to vary
the analytical principles, depending on the chemical and
physical-chemical properties of analytes; 2. In some cases, mainly
in the study of hydrolytic enzymes, the natural s- strate must be
replaced by an artificial one,that is chromolytic,chromogenic,
chemiluminiscent,bioluminiscent,or fluorescent.
The immobilized biocatalyst (IMB) is a key component of
biotransformation systems that are used to transform substrates to
desired products. The impro- ment of biocatalyst properties has a
direct influence on the overall effectiveness of the process based
on the biotransformation. The basic catalytic characte- stics of
biocatalyst that are followed include kinetic properties, pH
optima, stability,and inhibition. The investigation of catalytic
properties of immobilized enzymes is still a time consuming
procedure and is not always simple. In the 1980s,a major effort was
made to standardize the rules by which IMB is char- terized. The
Working Party of EFB on immobilized biocatalysts has formul- ed
principles of individual methods, among them the requirement of
kinetic characterization [1]. It was recommended to use a
packed-bed reactor,equipped with temperature control and with
infinite flow circulation. The system should be equipped with a
post-column unit to measure the time-dependence of the product or
substrate concentration [2, 3], the most commonly used analytical
methods being spectrophotometry, chemiluminiscence, automatic
titration, bioluminiscence, chromatography, polarimetry, and
biosensors based on the oxygen electrode. There are two main
drawbacks to the application of these methods: 1. The need to vary
the analytical principles, depending on the chemical and
physical-chemical properties of analytes; 2. In some cases, mainly
in the study of hydrolytic enzymes, the natural s- strate must be
replaced by an artificial one,that is chromolytic,chromogenic,
chemiluminiscent,bioluminiscent,or fluorescent.
Die Biotechnologie befindet sich augenblicklich in einem standigen
Wandel. Dinge, die heute neu erscheinen, sind schon in Klirze
veraltet. Grundsatze, Regeln und Be griffe andern sich standig oder
werden von Arbeitskreis zu Arbeitskreis anders defi niert. Da die
Zahl der Lehrbficher in der Biotechnologie noch immer recht klein
ist, fehlt ein "solides biotechnologisches" Basiswissen.
Zusammenfassende Studien fiber Teilgebiete der Biotechnologie sind
notig, urn einen schnellen, intensiven Austausch neuer
Forschungsbereiche und -ideen zu gewiihrleisten. Sie sollten eine
Zusammen fassung der bisherigen relevanten Forschungsarbeiten
beinhalten und so ein gewisses "Basiswissen" schaffen. Da ich mich
im Rahmen meiner Habilitationsarbeit mit einem Teilgebiet der Bio
technologie - der Beobachtung des Zellzustands und der Zellumgebung
bei Biopro zessen - beschiiftigte und viele Ergebnisse aus der
Literatur und der eigenen For schung beschrieben habe, erschien es
mir einleuchtend, diese Erfahrungen im Rah men dieser Stu die einem
breiteren Interessentenkreis zur Diskussion bereitzustellen. Die
Studie kann nicht den Anspruch der Vollkommenheit erheben, gtbt
aber sicher einen guten Oberblick zu dem Thema. Die Studie entstand
auf der Basis meiner Habilitationsarbeit, die ich im Zeitraum von
1985 und Juli 1989 angefertigt habe. Ein GroBteil der in ihr
beschriebenen For schung wurde am Institut fUr Technische Chemie
der Universitat Hannover, ein Teil am Department of Chemical
Engineering am California Institute of Technology (Pasadena, USA)
betrieben."
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