IMMOBILIZATION OF CELLULASE ENZYMES ON EPOXY SEPABEADS? FOR THE HYDROLYSIS OF LIGNOCELLULOSIC MATERIALS

摘要

For several years, international research has been performing the optimization of cellulose enzymatichydrolysis to produce bioethanol. Enzymes low specific activity and fast deactivation are relevant problems in thedevelopment of this process and additional improvements are needed to make bioethanol comparable to traditionalfuels. Enzymes immobilization facilitates biocatalyst recovery and reuse. Furthermore, enzymes immobilizationavoids autolysis and increase enzyme stability allowing continuous operation for long periods, reducing processescosts and making this process more suitable to industrial scale up.In this paper, commercial cellulase enzymes (Celluclast 1.5 and Novozym 188) immobilization on epoxy Sepabeads?has been investigated. These supports ensure a mild physical adsorption of the enzymes followed by a very fastintramolecular covalent binding with the material epoxy groups. Data show that 60% of loaded Celluclast proteinswere adsorbed by the support and that more than 90% of these proteins remained stably linked even after repeatedwashings. Similar results were obtained with Novozym.Novozym enzyme immobilized was used for β-glucosidase activity test. The first analyses show that immobilizedNovozym activity is comparable with free enzyme. The paper shows preliminary results about immobilizedbiocatalysts performances.