Effects of Porous Polyacrylic Resin Parameters on Candida antarctica Lipase B Adsorption, Distribution, and Polyester Synthesis Activity

Abstract

Polyacrylic resins were employed to study how immobilization resin particle size influences Candida antarctica Lipase B (CALB) loading, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed more rapidly on smaller beads. Saturation occurred in less than 30 seconds and 48 h for beads with diameters 35 and 560-710 μm, respectively. Infrared microspectroscopy showed that CALB forms protein loading fronts for resins with particle sizes 560-710 and 120 μm while CALB appears evenly distributed throughout 35 μm resins. The fraction of active CALB molecules adsorbed onto resins not influenced by particle size was less than 50 %. At about 5% w/w CALB loading, decrease in the immobilization support diameter from 560-710 to 120, 75 and 35 μm increased conversion of e-CL to polyester (20 to 36, 42 and 61%, respectively, at 80 min). Similar trends were observed for condensation polymerizations of 1,8-octanediol and adipic acid.