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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Development of a chimeric hemicellulase to enhance the xylose production and thermotolerance

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Author(s):
Diogo, Jose A. [1, 2] ; Hoffmam, Zaira B. [1, 2] ; Zanphorlin, Leticia M. [1] ; Cota, Junio [1] ; Machado, Carla B. [1] ; Wolf, Lucia D. [1] ; Squina, Fabio [1] ; Damasio, Andre R. L. [1] ; Murakami, Mario T. [2] ; Ruller, Roberto [1]
Total Authors: 10
Affiliation:
[1] CNPEM, Lab Nacl Ciencia & Tecnol Bioetanol CTBE, Campinas, SP - Brazil
[2] CNPEM, Lab Nacl Biociencias LNBio, Campinas, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Enzyme and Microbial Technology; v. 69, p. 31-37, FEB 2015.
Web of Science Citations: 10
Abstract

Xylan is an abundant plant cell wall polysaccharide and its reduction to xylose units for subsequent biotechnological applications requires a combination of distinct hemicellulases and auxiliary enzymes, mainly endo-xylanases and beta-xylosidases. In the present work, a bifunctional enzyme consisting of a GH11 endo-1,4-beta-xylanase fused to a GH43 beta-xylosidase, both from Bacillus subtilis, was designed taking into account the quaternary arrangement and accessibility to the substrate. The parental enzymes and the resulting chimera were successfully expressed in Escherichia coli, purified and characterized. Interestingly, the substrate cleavage rate was altered by the molecular fusion improving at least 3-fold the xylose production using specific substrates as beechwood xylan and hemicelluloses from pretreated biomass. Moreover, the chimeric enzyme showed higher thermotolerance with a positive shift of the optimum temperature from 35 to 50 degrees C for xylosidase activity. This improvement in the thermal stability was also observed by circular dichroism unfolding studies, which seems to be related to a gain of stability of the beta-xylosidase domain. These results demonstrate the superior functional and stability properties of the chimeric enzyme in comparison to individual parental domains, suggesting the molecular fusion as a promising strategy for enhancing enzyme cocktails aiming at lignocellulose hydrolysis. (C) 2014 Elsevier Inc. All rights reserved. (AU)

FAPESP's process: 13/10443-7 - Bioprospecting and construction of hemicellulases for the production of xylose from hydrolyzate licor pentoses and their use in fermentative xylitol production
Grantee:José Alberto Diogo
Support type: Scholarships in Brazil - Master
FAPESP's process: 08/58037-9 - Library generation for biomass-conversion enzymes from soil metagenome
Grantee:Fábio Márcio Squina
Support type: Program for Research on Bioenergy (BIOEN) - Young Investigators Grants
FAPESP's process: 11/14200-6 - Functional studies of microbial hemicellulases with potential biotechnological application in biorefinery of hemicellulosic biomass
Grantee:Zaira Bruna Hoffmam
Support type: Scholarships in Brazil - Master