Xylanase and beta-Xylosidase from Penicillium janczewskii: Production, Physico-chemical Properties, and Application of the Crude Extract to Pulp Biobleaching
Data
2013-01-01
Autores
Terrasan, Cesar R. F.
Temer, Beatriz [UNESP]
Sarto, Camila
Silva Junior, Francides G.
Carmona, Eleonora C. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
North Carolina State Univ Dept Wood & Paper Sci
Resumo
Extracellular xylanase and beta-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 beta-xylosidase were 7 days, pH 6.5, at 30 degrees C and 8 days, pH 5.0, at 25 degrees C, respectively. The xylanase exhibited optimal activity in pH 5.0 at 50 degrees C and the beta-xylosidase in pH 4.0 at 75 degrees C. The xylanase was more stable at pH 6.0 to 9.5, while the beta-xylosidase remained stable at pH ranging from 1.6 to 5.5. The xylanase half-life (T-50) at 40, 50, and 60 degrees C was 183, 15, and 3 min, respectively. beta-xylosidase half-life was 144, 8, and 4 min at 50, 65, and 75 degrees 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.
Descrição
Palavras-chave
Xylanolytic enzymes, Penicillium janczewskii, Enzyme production, Enzyme characterization, Pulp biobleaching
Como citar
Bioresources. Raleigh: North Carolina State Univ Dept Wood & Paper Sci, v. 8, n. 1, p. 1292-1305, 2013.