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

Autor(es)

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]

Afiliação do(s) autor(es)

^[1] CNPEM, Lab Nacl Ciencia & Tecnol Bioetanol CTBE, Campinas, SP - Brazil

^[2] CNPEM, Lab Nacl Biociencias LNBio, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Enzyme and Microbial Technology; v. 69, p. 31-37, FEB 2015.
• Citações Web of Science: 10

Resumo

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)

• Processo FAPESP: 11/14200-6 - Estudos funcionais de hemicelulases microbianas com potencial aplicação biotecnológica em biorrefinarias de biomassas hemicelulósicas
• Beneficiário: Zaira Bruna Hoffmam
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 13/10443-7 - Bioprospecção e construção de hemicelulases para a produção de xilose a partir de hidrolisado de licor de pentoses e sua utilização na produção de xilitol via fermentativa
• Beneficiário: José Alberto Diogo
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 08/58037-9 - Geração de biblioteca para conversão enzimática de biomassa a partir de metagenoma do solo
• Beneficiário: Fábio Márcio Squina
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Jovens Pesquisadores