Chapter 15
Membranes of Cellulose Derivatives as Supports for Immobilization of Enzymes 1
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R. Lagoa , D. Murtinho , and M. H. Gil
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Department of Chemical Engineering, University of Coimbra, 3000 Coimbra, Portugal Department of Chemistry, University of Coimbra, 3000 Coimbra, Portugal
Downloaded by UNIV OF ROCHESTER on August 28, 2013 | http://pubs.acs.org Publication Date: March 25, 1999 | doi: 10.1021/bk-1999-0723.ch015
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Membranes were prepared from cellulosic derivatives (cellulose acetate, cellulose propionate and cellulose acetate butyrate). Their chemical and physical properties were determined by DSC, water vapor sorption and contact angle evaluation. Catalase, alcohol oxidase and glucose oxidase were covalently linked to these membranes and catalytic activity and stability were examined. The activity results of the immobilization and the stability of the coupled enzymes were found to correlate well with the studied properties of the supports. Cellulose acetate membranes yielded the most active conjugate of support and enzyme. Highly hydrophobic membranesfrompropionate and butyrate esters of cellulose yielded lower activities, but better storage stability.
Immobilized enzymes, proteins and cells offer advantages because they can be easily handled and recovered; i.e., easily removedfromreaction mixtures and repeatedly used in continuous processes. In this way, expensive enzymes can be economically recycled for industrial and clinical applications. To be of value, enzymes attached to a support must retain some of their initial activity. The activity retained by the immobilized enzyme is dependent on a large number of parameters, including the coupling method, the enzyme used and the nature of the support. Due to their good chemical and physical properties, cellulosic materials have been widely used as supports for enzyme immobilization (7,2). Examples include membranes for hemodialysis (5), for reverse osmosis (4), for microfiltration (5), in biosensors (/) and as chromatographic supports (
