Results
Title

Characterization of direct cellulase immobilization with superparamagnetic nanoparticles.

Authors

Xu, Jingliang; Huo, Shuhao; Yuan, Zhenhong; Zhang, Yu; Xu, Huijuan; Guo, Ying; Liang, Cuiyi; Zhuang, Xinshu

Abstract

Methods of cellulase immobilization on magnetic particles via glutaraldehyde binding were studied. The binding was confirmed by transmission electronic microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and vibrating sample magnetometry (VSM). Samples analyzed by TEM and XRD showed that the magnetic particles with or without bound cellulase were all nanosized particles with a mean diameter of 11.5 nm, and the binding process did not cause significant changes in particle size and structure. Analysis by FTIR showed that the binding of cellulase to the magnetic nanoparticles might be via covalent bonding between residual amine groups on Fe3O4 nanoparticles and amine groups of the cellulase. The VSM analysis showed that magnetic nanoparticles with or without bound cellulase were all superparamagnetic. The immobilized cellulase had a wider pH and temperature range and improved storage stability compared with the free enzyme. Determination of the Michaelis constants revealed that the immobilized cellulase had a greater affinity for the cellulosic substrate than the free enzyme. The immobilized cellulase showed better performance on hydrolysis of steam-exploded corn stalks than of bleached sulfite bagasse pulp.

Subjects

IMMOBILIZED enzymes; CELLULASE; MAGNETIC materials; PARAMAGNETISM; NANOPARTICLES; GLUTARALDEHYDE; CHEMICAL bonds; FOURIER transform infrared spectroscopy

Publication

Biocatalysis & Biotransformation, 2011, Vol 29, Issue 2/3, p71

ISSN

1024-2422

Publication type

Academic Journal

DOI

10.3109/10242422.2011.566326