Direct synthesis of zeolites self-bonded pellets for biocatalyst immobilization

In this work, the preparation, by direct synthesis, of Silicalite-1 self-bonded pellets as supports for immobilization of lipase enzyme is presented. The Silicalite-1 pellets have been prepared in view of the results obtained from the lipase enzyme adsorption on the most suitable supports in powder form. The different pellet preparation procedures strongly influence the final properties of the product. The main synthesis parameter that leads to pellets having high performance, especially regarding the crystal cohesion in aqueous system, is the alkalinity of the synthesis mixture. All possible attachment sites of the support surface of the self-bonded pellets prepared without a binding agent are available to the enzyme. The amount of the enzyme retained on the pellet surface (275 mg/g) is comparable to the amount adsorbed on the powder Silicalite-1 support. © 2005 Elsevier B.V. All rights reserved.