Abstract: Amylase was precipitated with 80% isopropanol followedcross-linking with glutaraldehyde to obtain cross-linked amylase aggregates (CLEAs-A). Then CLEAs-A was covalently immobilized on a macroporous polymer carrier containing a phenanthrene skeleton to obtain immobilized CLEAs-A. Herein, various process parameters were systematically evaluated. Moreover, the enzymatic properties and physical structure of immobilized CLEAs-A were investigated. The thermal and storage stability were improved remarkably as compared with those of the free amylase. After seventh repeated use, the activity recovery of immobilized CLEAs-A was still as high as 63.29%. Furthermore, scanning electron microscopy and porosity measurements indicated the surface and pore structure of immobilized CLEAs-A. The proposed immobilization strategy would provide a general approach for preparing immobilized enzymes with robust and high bio-catalytic properties for in industrial production.

Key words: amylase, cross-linked amylase aggregates (CLEAs-A), immobilized CLEAs-A, phenanthrene skeleton