Biotechnology Letters, Vol.38, No.9, 1579-1585, 2016
Covalent immobilization of Agrobacterium radiobacter epoxide hydrolase on ethylenediamine functionalised epoxy supports for biocatalytical synthesis of (R)-epichlorohydrin
To improve the operational stability and reusability of an epoxide hydrolase (EH) for the biosynthesis of optically active epoxides. A covalently immobilization strategy was employed to improve the stability of Agrobacterium radiobacter EH by using ethylenediamine (EDA)-functionalised epoxy resin LX-1000EP as carrier. Under the optimal conditions, the activity recovery of immobilized enzyme was 72 % and the specific activity was 634 U/g. Immobilized EH exhibited significantly enhanced thermal stability with a half-life of more than 6.8-fold at 50 A degrees C than that of the free enzyme. A gram-scale kinetic resolution of (R,S)-epichlorohydrin using immobilized preparation as biocatalyst was performed and (R)-epichlorohydrin was obtained with 35 % yield and 99 % enantiomeric excess. The immobilized EH showed good operational stability and even after six reactions, it retained > 85 % of the initial activity. The operational stability and recyclability of immobilized EH on an EDA-functionalized epoxy supports demonstrated its potential for producing (R)-epichlorohydrin.
Keywords:Covalent immobilization;(R)-epichlorohydrin;Epoxide hydrolas;Ethylenediamine;Epoxy supports;Biocatalytical synthesis