title: Immobilization of β-glucosidase on a magnetic nanoparticle improves thermostability: application in cellobiose hydrolysis.
abstract: The objective of the present work was to develop a thermostable β-glucosidase through immobilization on a nanoscale carrier for potential application in biofuel production. β-Glucosidase (BGL) from Aspergillus niger was immobilized to functionalized magnetic nanoparticles by covalent binding. Immobilized nanoparticles showed 93% immobilization binding. Immobilized and free BGL were characterized using Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Free and immobilized enzyme exhibited different pH-optima at pH 4.0 and 6.0, respectively, but had the same temperature optima at 60 °C. Michaelis constant (KM) was 3.5 and 4.3mM for free and immobilized BGL. Thermal stability of the immobilized enzyme was enhanced at 70 °C. The immobilized nanoparticle-enzyme conjugate retained more than 50% enzyme activity up to the 16th cycle. Maximum glucose synthesis from cellobiose hydrolysis by immobilized BGL was achieved at 16 h.
authors: Centre for Chemistry and Biotechnology, Deakin University, Geelong Technology Precinct, Geelong, Victoria 3217, Australia.
authors: Madan L
authors: ML
authors: Verma
authors: Rajneesh
authors: R
authors: Chaudhary
authors: Takuya
authors: T
authors: Tsuzuki
authors: Colin J
authors: CJ
authors: Barrow
authors: Munish
authors: M
authors: Puri
mesh_terms: D055162:Biocatalysis; D002475:Cellobiose / Q000378:metabolism*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009598:Nitrophenylgalactosides / Q000378:metabolism; D059027:Recycling; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D058185:Magnetite Nanoparticles; D002475:Cellobiose; D009598:Nitrophenylgalactosides; C059200:4-nitrophenylgalactoside; D001617:beta-Glucosidase