Xylanase and β-Xylosidase from Penicillium janczewskii: Production, Physico-Chemical properties, and application of the crude extract to pulp biobleaching

• Autor(a) principal: Terrasan, César R. F.
• Data de Publicação: 2013
• Outros Autores: Temer, Beatriz [UNESP], Sarto, Camila, Silva Júnior, Francides G., Carmona, Eleonora C. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_08_1_1292_Terrasan_Xylanase_Penicillium; http://hdl.handle.net/11449/74549
• topic: Enzyme characterization; Enzyme production; Penicillium janczewskii; Pulp biobleaching; Xylanolytic enzymes; Biobleaching; Bast fibers; Chemical properties; Kraft pulp; Optimization; Enzyme activity; Chemical Properties; Enzymes; Fibers; Kraft Pulps; Phloem

Extracellular xylanase and β-xylosidase production by a Penicillium janczewskii strain were investigated in liquid cultures with xylan from oat spelts under different physical and chemical conditions. The selected conditions for optimized production of xylanase and β-xylosidase were 7 days, pH 6.5, at 30 °C and 8 days, pH 5.0, at 25 °C, respectively. The xylanase exhibited optimal activity in pH 5.0 at 50 °C and the β- xylosidase in pH 4.0 at 75 °C. The xylanase was more stable at pH 6.0 to 9.5, while the β-xylosidase remained stable at pH ranging from 1.6 to 5.5. The xylanase half-life (T50) at 40, 50, and 60 °C was 183, 15, and 3 min, respectively. β-xylosidase half-life was 144, 8, and 4 min at 50, 65, and 75 °C, respectively. When applied to the biobleaching of Eucalyptus kraft pulp, xylanase dosages of 2 and 4 U/g dried pulp reduced, respectively, kappa number by 3.0 and 3.3 units after 1 h treatment, demonstrating that the use of P. janczewskii xylanases in this process is quite promising. The pulp viscosity was not altered, confirming the absence of cellulolytic enzymes in the fungal extract.