Characterization and kinetic analysis of a thermostable GH3 β-glucosidase from Penicillum brasilianum
Artikel i vetenskaplig tidskrift, 2010

A GH3 β-glucosidase (BGL) from Penicillum brasilianum was purified to homogeneity after cultivation on a cellulose and xylan rich medium. The BGL was identified in a genomic library, and it was successfully expressed in Aspergillus oryzae. The BGL had excellent stability at elevated temperatures with no loss in activity after 24 h of incubation at 60°C at pH 4-6, and the BGL was shown to have significantly higher stability at these conditions in comparison to Novozym 188 and to other fungal GH3 BGLs reported in the literature. The BGL had significant lower afinity for cellobiose compared with the artificial substrate para-nitrophenyl-β-D-glucopyranoside (pNP-Glc)and further, pronounced substrate inhibition using p-NP-Glc. Kinetic studies demonstrated the high importance of using cellbiose as substrate and glucose as inhibitor to describe the inhibition kinetics of BGL taking place during cellulose hydrolysis. A novel assay was developed to characterize this glucose inhibition on cellobiose hydrolosis. The assay uses labelled glucose-13C6 as inhibitor and subsequent mass spectrometry analysis to quantify the hydrolysis rates

Fungal expression

Purification

Cellulose hydrolosis

Kinetics

Glucose inhibition

Författare

K.B.R.M. Krogh

Novozymes AS

Danmarks Tekniske Universitet

P.V. Harris

Novozymes Biotech, Inc.

Carsten L. Olsen

Fungal Gene Technology

Katja Salomon Johansen

Detergent Applications II

Jesper Hojer-Pedersen

Novozymes AS

Danmarks Tekniske Universitet

Johan Börjesson

Lunds Universitet

Novozymes AS

Lisbeth Olsson

Danmarks Tekniske Universitet

Chalmers University of Technology

Wallenberg Wood Science Center (WWSC)

Applied Microbiology and Biotechnology

0175-7598 (ISSN) 1432-0614 (eISSN)

Vol. 86 143-154

Ämneskategorier

Industriell bioteknik

DOI

10.1007/s00253-009-2181-7