Abstract

The Bxl5-gene encoding a GH3 glycoside hydrolase of Chrysosporium lucknowense Cl was successfully cloned, the homologous recombinant product was secreted, purified and characterized. Bxl5 (120 +/- 5 kDa) was able to hydrolyze low molecular weight substrates and polysaccharides containing p-glucosidic as well as beta-xylosidic residues. The K-m and V-max/E values were found to be 0.3 mM and 88 s(-1) on p-nitrophenyl-beta-D-glucopyranoside (PNPG), and 13.5 mM and 1.8 s(-1) on p-nitrophenyl-beta-D-xylopyranoside (PNPX). Optimal pH and temperature for Bxl5 were 4.6 and 75 degrees C for the PNPG hydrolysis, and 5.0-5.5 and 70 degrees C for PNPX hydrolysis. The enzyme was quite stable when incubated at elevated temperatures up to 65 degrees C. Bxl5 hydrolyzes polymeric beta-glucans by the exo-mechanism allowing their complete conversion to D-glucose and is effective for xylan hydrolysis in combination with endo-acting xylan-degrading enzymes. The enzyme seems to be a very promising for bioconversion purposes. (C) 2012 Elsevier Ltd. All rights reserved.

Keywords

GH family 3; Hemicellulose; Enzymatic hydrolysis; Glucose; Xylose

Published in

Bioresource Technology
2012, Volume: 112, pages: 345-349

UKÄ Subject classification

Biochemistry and Molecular Biology


Publication identifier

DOI: https://doi.org/10.1016/j.biortech.2012.02.105

Permanent link to this page (URI)

https://res.slu.se/id/publ/84282