Xylanase from Fusarium heterosporum: Properties and influence of thiol compounds on xylanase activity

  • Paulo Ricardo Heinen
  • Caroline Henn
  • Rosane Marina Peralta
  • Adelar Bracht
  • Rita de Cássia Garcia Simão
  • Jose Luís da Conceição Silva
  • Maria de Lourdes TM Polizeli
  • Marina Kimiko Kadowaki

Abstract

The properties of xylanase purified from Fusarium heterosporum that was grown in barley-brewing residue under solid-state fermentation and the effects of thiol compounds on the reactivation of the metal ion-inhibited xylanase were investigated. Xylanase was purified to homogeneity by ion exchange chromatography, and its molecular mass was estimated to be 19.5 kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH for the xylanase was 5.0, and it was stable in acidic pH (4.5 to 5.5), where it retained more than 87% of its activity after 24 h. The optimum temperature was 50°C, and it had a half-life of 53 min at 45°C. The apparent Km and Vmax values for the xylanase were 5.63 mg/ml and 800 μmol/mg/min, respectively. Ba2+, Ca2+, Mg2+ and the thiol compounds β-mercaptoethanol and dithiothreitol (DTT) enhanced xylanase activity, while Hg2+, Pb2+ and Zn2+ strongly inhibited enzyme activity. Furthermore, this xylanase had an alternative mode of regulation in the presence of thiol compounds because the enzyme was able to recover its catalytic activity after inhibition by heavy metal ions.

Keywords: Hemicellulase, fungus, solid-state fermentation, barley brewing residue, thiol compounds

African Journal of Biotechnology, Vol. 13(9), pp. 1047-1055, 26 February, 2014

Author Biographies

Paulo Ricardo Heinen
Departamento de Bioquímica- FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
Caroline Henn
Divisão de Reservatório - MARR.CD, Itaipu Binacional - Foz do Iguaçu, Paraná, Brazil
Rosane Marina Peralta
Departamento de Biquímica - Universidade Estadual de Maringá - Maringá, Paraná, Brazil
Adelar Bracht
Departamento de Biquímica - Universidade Estadual de Maringá - Maringá, Paraná, Brazil
Rita de Cássia Garcia Simão
Centro de Ciências Médicas e Farmacêuticas - UNIOESTE - Cascavel, Paraná, Brazil
Jose Luís da Conceição Silva
Centro de Ciências Médicas e Farmacêuticas - UNIOESTE - Cascavel, Paraná, Brazil
Maria de Lourdes TM Polizeli
Departamento de Bioquímica- FMRP, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
Marina Kimiko Kadowaki
Centro de Ciências Médicas e Farmacêuticas - UNIOESTE - Cascavel, Paraná, Brazil
Published
2015-05-27
Section
Articles

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eISSN: 1684-5315