Polyethyleneimine in immobilization of biocatalysts

A variety of polymers with amino pendant groups have been accepted as suitable enzyme carriers. A number of synthesis strategies and techniques are adopted to anchor enzymes. The polymers are activated through derivatization either prior to or during adsorption to facilitate the covalent binding of enzyme. Polyethyleneimine (PEI), with the highest concentration of amino groups, has found acceptance as a carrier in a number of industrial immobilized biosystems. The two forms of PEI known are the linear crystalline type and the more important amorphous branched structure with a distribution of primary, secondary, and tertiary amino groups in the ratio 1:2:1. The primary and secondary amino groups are conveniently modified to generate facile enzyme carriers. A number of patents have been filed on the use of PEI to bind a rich variety of enzymes and whole cells. This review is primarily a compilation of these reports and purports to highlight the potential of PEI.