Valenzuela R., Castro J.F., Parra M.C., Baeza J., Free J.
Biotechnology Center, University of Concepcion, CL
Keywords: Beta-glucosidase, immobilization, magnetite nanoparticles, saccharification, superparamagnetism
Beta-glucosidase from T. reesei was successfully immobilized on synthetic superparamagnetic magnetite (Fe3O4) nanoparticles with a mean diameter of 10 nm, silanized and amino-functionalized with 3-aminopropyltriethoxysilane (3-APTS). When silanized and coated the saturation magnetization decreased from 72 emu g-1 to 55.9 emu g-1 without losing their superparamagnetic features. The concentration of enzyme immobilized on 1.0 g of silanized magnetite and funtionalized with glutaraldehyde was 0.10 g L-1; the activity retention after immobilization was 98% and the enzyme was stable for at least 45 days. The immobilized beta-glucosidase was used to supplement cellulase in the enzymatic hydrolysis of three substrates: wheat straw pretreated by steam explosion (WS-SE), E. globulus pretreated by hydrothermolysis (EG-H) and pulp from hydrothermolysis followed by alkaline extraction (EG-HA). The hydrolysis yields for every pretreated material, using immobilized beta-glucosidase and free cellulase, were 76.1%, 83.6% and 75.6%, respectively, obtaining higher hydrolysis yields compared to those obtained only with cellulase. These yields were 10% lower than the yields reached with cellulase supplemented with free beta-glucosidase. The immobilized beta-glucosidase was magnetically recovered and reused twice. The differences in the hydrolysis yields were not significant (p>0.05) for WS-SE and EG-HA.
Journal: TechConnect Briefs
Volume: Technical Proceedings of the 2011 Clean Technology Conference and Trade Show
Published: June 13, 2011
Pages: 119 - 122
Industry sector: Energy & Sustainability
Topic: Biofuels & Bioproducts
ISBN: 978-1-4398-8189-7