Influence of Textural Properties of Divinylbenzene Copolymers on the Immobilization of Lipase B from Candida antarctica

Abstract

Previous studies have investigated the preparation of heterogeneous biocatalysts based on the immobilization of lipases on distinct types of supports. However, few works have investigated the influence of the textural properties of these supports on the immobilization parameters. Thus, the present article reports the preparation of copolymers based on divinylbenzene by aqueous suspension polymerizations, using different amounts of porogenic agents to prepare particles with distinct textural properties. The particles were used for immobilization of lipase from Candida antarctica fraction B and the performance of the biocatalysts was evaluated in hydrolysis reactions, using p-nitrophenyl laurate as substrate. The use of Sty/DVB particles resulted in higher immobilization yields (89.5% and 99.2%) and higher hydrolytic activities, when compared to the Sty/VBC/DVB particles. Particularly, the increase of the pore diameters of the particles resulted in higher immobilization yields. Also, the hydrolytic activities depended simultaneously on the average pore diameter, porosity, and specific area (the most influential variable) of the supports. Thus, it was observed that the distinct morphological features of the polymer support can exert significant and conflicting effects on the final biocatalyst performance, since the specific surface area is normally expected to decrease with the increase of the average pore size.

Keywords:
Styrene-divinylbenzene copolymers; porous polymers; heterogeneous biocatalysts; CALB; enzyme immobilization