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Free and immobilized Aspergillus niger epoxide hydrolase-catalyzed hydrolytic kinetic resolution of racemic p-chlorostyrene oxide in a neat organic solvent medium

Paper ID Volume ID Publish Year Pages File Format Full-Text
35026 45069 2010 7 PDF Available
Title
Free and immobilized Aspergillus niger epoxide hydrolase-catalyzed hydrolytic kinetic resolution of racemic p-chlorostyrene oxide in a neat organic solvent medium
Abstract

An enantio- and regioselective hydrolytic kinetic resolution (HKR) of racemic p-chlorostyrene oxide (rac-pCSO) was achieved by epoxide hydrolase (EH) from recombinant Aspergillus niger in a selected neat organic solvent medium. The solid free EH was reused four times in repeated-batch reactors; however, the relative activity as well as the enantiomeric ratio (E-value) of this EH decreased from 100 to 20% and from 68 to 23, respectively. In order to overcome the diffusion hindrance, due to the accumulation of the hydrophilic diol in the enzyme micro-environment, and thereby to improve the operational stability of EH after recycling, strategies consisting of the immobilization of EH and the use of a binary organic solvent as the reaction medium were successfully applied. Although the highest protein immobilization yield (82%) and retention of EH activity (142%) in heptane were obtained upon the immobilization of EH on Accurel EP, the E-value and the operational stability of the resulted EH immobilizate after recycling were reduced as compared to the free EH. In contrast, the nonporous DEAE-cellulose improved the operational stability of EH by more than twofold. On the other hand, both the HKR efficiency and the operational stability of A. niger EH were found to be modest to excellent in various binary organic solvent mixtures of heptane and dioxane, depending on their ratio resulting in different Log P.

Keywords
Epoxide hydrolase; Aspergillus niger; Organic solvent; Immobilization; Resolution; Operational stability
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Free and immobilized Aspergillus niger epoxide hydrolase-catalyzed hydrolytic kinetic resolution of racemic p-chlorostyrene oxide in a neat organic solvent medium
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Publisher
Database: Elsevier - ScienceDirect
Journal: Process Biochemistry - Volume 45, Issue 2, February 2010, Pages 210–216
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us