Immobilized copper-ion affinity adsorbent based on a cross-linked beta-cyclodextrin polymer for adsorption of Candida rugosa lipase

Lipase from Candida rugosa was immobilized on a beta-cyclodextrin-based polymer by adsorption and subsequent cross-linking with epichlorohydrin (EP-CD). The ligand iminodiacetic acid (IDA) was then bonded with the cross-linked beta-cyclodextrin (EP-CD-IDA). This affinity adsorbent was further chelated with Cu2+ for the purpose of binding affinity and stability. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. Results showed that 266 mu g protein with an activity of 17.85 U was bound per gram of matrix, giving 188% of the specific activity of the free enzyme and a total recovered activity of 79.7% under the optimum conditions. The pH and thermal stabilities of lipase were improved after immobilization on the beta-cyclodextrin-based polymer (EP-CD-IDA-Cu2+). In addition, experimental results indicated that the residual activity of the immobilized lipase was 50% after eight cycles of reuse.