title: A novel thermostable xylanase GH10 from Malbranchea pulchella expressed in Aspergillus nidulans with potential applications in biotechnology.
abstract: BACKGROUND
  The search for novel thermostable xylanases for industrial use has intensified in recent years, and thermophilic fungi are a promising source of useful enzymes. The present work reports the heterologous expression and biochemical characterization of a novel thermostable xylanase (GH10) from the thermophilic fungus Malbranchea pulchella, the influence of glycosylation on its stability, and a potential application in sugarcane bagasse hydrolysis.
  
  
  RESULTS
  Xylanase MpXyn10A was overexpressed in Aspergillus nidulans and was active against birchwood xylan, presenting an optimum activity at pH 5.8 and 80°C. MpXyn10A was 16% glycosylated and thermostable, preserving 85% activity after 24 hours at 65°C, and deglycosylation did not affect thermostability. Circular dichroism confirmed the high alpha-helical content consistent with the canonical GH10 family (β/α)8 barrel fold observed in molecular modeling. Primary structure analysis revealed the existence of eight cysteine residues which could be involved in four disulfide bonds, and this could explain the high thermostability of this enzyme even in the deglycosylated form. MpXyn10A showed promising results in biomass degradation, increasing the amount of reducing sugars in bagasse in natura and in three pretreated sugarcane bagasses.
  
  
  CONCLUSIONS
  MpXyn10A was successfully secreted in Aspergillus nidulans, and a potential use for sugarcane bagasse biomass degradation was demonstrated.
authors: Immunology and Biochemistry Department of Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP Brazil.
authors: Liliane Fc
authors: LF
authors: Ribeiro
authors: Immunology and Biochemistry Department of Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP Brazil.
authors: Rosymar C
authors: RC
authors: De Lucas
authors: Immunology and Biochemistry Department of Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP Brazil.
authors: Gabriela L
authors: GL
authors: Vitcosque
authors: Immunology and Biochemistry Department of Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP Brazil.
authors: Lucas F
authors: LF
authors: Ribeiro
authors: Chemistry Department of Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - USP, Ribeirão Preto, SP Brazil ; Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Campinas, SP Brazil.
authors: Richard J
authors: RJ
authors: Ward
authors: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Campinas, SP Brazil.
authors: Marcelo V
authors: MV
authors: Rubio
authors: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Campinas, SP Brazil.
authors: Andre Rl
authors: AR
authors: Damásio
authors: Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Campinas, SP Brazil.
authors: Fabio M
authors: FM
authors: Squina
authors: Department of Chemistry, The University of York, York, UK.
authors: Rebecca C
authors: RC
authors: Gregory
authors: Department of Chemistry, The University of York, York, UK.
authors: Paul H
authors: PH
authors: Walton
authors: Biology Department of Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - USP, Av. Bandeirantes, 3900, Ribeirão Preto, SP 14040-901 Brazil.
authors: João A
authors: JA
authors: Jorge
authors: Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK USA.
authors: Rolf A
authors: RA
authors: Prade
authors: Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
authors: Marcos S
authors: MS
authors: Buckeridge
authors: Biology Department of Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - USP, Av. Bandeirantes, 3900, Ribeirão Preto, SP 14040-901 Brazil.
authors: Maria de Lourdes Tm
authors: Mde L
authors: Polizeli
keywords: Biomass degradation; Glycosylation; Heterologous expression; Malbranchea; Sugarcane bagasse; Thermostability; Xylanase