Membrane-type immobilized enzyme reactors for use in flow-injection analysis

Cliffe, Stephen; Filippini, Claudio; Schneider, Markus; Fawer, Matthias S.

doi:10.1016/0003-2670(92)85325-z

Cited by 9 publications

(2 citation statements)

References 11 publications

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“…For example, laccase immobilized in a gelatin matrix retains 90% of its activity after 4 months of storage at 4 °C compared to laccase in solution, which retains only 50% of its activity when stored under the same conditions . Other examples include immobilization of laccase onto different types of glass beads (e.g., round, porous). − In general, when laccase is immobilized onto porous glass beads treated first with 3-aminopropyltriethoxysilane followed by glutaraldehyde, both the immobilization yields (100%) and retention of activity (90%) are very high. Although this method of immobilization does not change the optimal pH and temperature, the specific activity of immobilized laccase is higher than that of the enzyme in solution, suggesting that the enzyme was purified further during the immobilization process …”

Section: Introductionmentioning

confidence: 99%

A Biopolymer Composite that Catalyzes the Reduction of Oxygen to Water

2007

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A biopolymer composite consisting of polypyrrole, ABTS, and laccase (PAL) was electrodeposited onto the surface of an electrode and was shown to catalyze the reduction of dioxygen to water under acidic conditions. The catalytic activity of this biopolymer composite is highest at pH 4, decreasing with increasing pH. The activity of laccase immobilized within this polymer composite was found to be higher than laccase dissolved in solution when methanol was present or at elevated temperatures.

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Section: Introductionmentioning

confidence: 99%

A Biopolymer Composite that Catalyzes the Reduction of Oxygen to Water

2007

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“…Membrane reactors are briefly discussed in four review papers [3,47,156,281], while Wong et al discuss in [4] the connection between reactor design and enzyme stabilization. Reactors in which Dextran-bound NAD + was retained on UF are presented in [282]. Membranetype immobilized enzyme reactors (with glucose oxidase, glutaminase, and laccase, respectively) were used in flowinjection analysis for the monitoring of glucose (during continuous cultivation of yeast), for ammonia and glutamate (during mammalian cell culture), and for studying the properties of immobilized laccase [283].…”

Section: Reactors For Redox Reactions Coupled To Coenzyme Regenerationmentioning

confidence: 99%

Redox Enzymes Used in Chiral Syntheses Coupled to Coenzyme Regeneration

Leonida¹

2001

CMC

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Due to their ability to perform reactions in a stereo- and regiospecific manner, while functioning under mild conditions of temperature and pH, enzymes are increasingly used for chiral synthesis in the pharmaceutical industry, in medicinal chemistry, agriculture, cosmetic and food industry. The oxidoreductases as catalysts require a coenzyme (cofactor) which functions as an electron carrier. If used in stoichiometric amounts the cost of coenzymes makes synthetic applications of redox enzymes prohibitively expensive for industrial applications. The present review updates previous discussions about the objectives of cofactor regeneration as a requirement for the applicability of enzymatic redox reactions, and about the strategies customarily used to this end. Different types of chiral syntheses coupled successfully to coenzyme regeneration (amino acid synthesis, lactone synthesis, synthetic reactions involving alcohols, hydroxy acid and steroid synthesis, deracemization) are then discussed. New catalysts, cross-linked enzyme crystals, prepared from redox enzyme are presented in a small paragraph together with some of their applications. Special attention is given to whole cells used in this type of synthesis and their advantages and disadvantages are presented in one paragraph. Finally, different reactors, within which were conducted chiral syntheses catalyzed by oxireductases and coupled to cofactor regeneration, are briefly discussed.

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