TY - JOUR

T1 - Characterization and kinetic analysis of a thermostable GH3 ß-glucosidase from Penicillium brasilianum

A1 - Krogh,Kristian Bertel Rømer

A1 - Harris,P.V.

A1 - Olsen,C.L.

A1 - Johansen,K.S.

A1 - Højer-Pedersen,Jesper Juul

A1 - Borjesson,J.

A1 - Olsson,Lisbeth

AU - Krogh,Kristian Bertel Rømer

AU - Harris,P.V.

AU - Olsen,C.L.

AU - Johansen,K.S.

AU - Højer-Pedersen,Jesper Juul

AU - Borjesson,J.

AU - Olsson,Lisbeth

PB - Springer

PY - 2010

Y1 - 2010

N2 - A GH3 beta-glucosidase (BGL) from Penicillium 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 60A degrees 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 affinity for cellobiose compared with the artificial substrate para-nitrophenyl-beta-d-glucopyranoside (pNP-Glc) and further, pronounced substrate inhibition using pNP-Glc. Kinetic studies demonstrated the high importance of using cellobiose 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 hydrolysis. The assay uses labelled glucose-C-13(6) as inhibitor and subsequent mass spectrometry analysis to quantify the hydrolysis rates.

AB - A GH3 beta-glucosidase (BGL) from Penicillium 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 60A degrees 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 affinity for cellobiose compared with the artificial substrate para-nitrophenyl-beta-d-glucopyranoside (pNP-Glc) and further, pronounced substrate inhibition using pNP-Glc. Kinetic studies demonstrated the high importance of using cellobiose 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 hydrolysis. The assay uses labelled glucose-C-13(6) as inhibitor and subsequent mass spectrometry analysis to quantify the hydrolysis rates.

KW - Fungal expression

KW - Kinetics

KW - Purification

KW - Cellulose hydrolysis

KW - Glucose inhibition

U2 - 10.1007/s00253-009-2181-7

DO - 10.1007/s00253-009-2181-7

JO - Applied Microbiology and Biotechnology

JF - Applied Microbiology and Biotechnology

SN - 0175-7598

IS - 1

VL - 86

SP - 143

EP - 154

ER -