Artigo
Xylanase and beta-Xylosidase from Penicillium janczewskii: Production, Physico-chemical Properties, and Application of the Crude Extract to Pulp Biobleaching
Registro en:
Bioresources. Raleigh: North Carolina State Univ Dept Wood & Paper Sci, v. 8, n. 1, p. 1292-1305, 2013.
1930-2126
WOS:000314632300103
WOS000314632300103.pdf
Autor
Terrasan, Cesar R. F.
Temer, Beatriz [UNESP]
Sarto, Camila
Silva Junior, Francides G.
Carmona, Eleonora C. [UNESP]
Resumen
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. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) UFSCar Fed Univ Sao Carlos, Dept Chem Engn, BR-13565905 Sao Carlos, SP, Brazil UNESP Univ Estadual Paulista, Biosci Inst, Dept Biochem & Microbiol, BR-13506900 Rio Claro, SP, Brazil ESALQ USP Univ Sao Paulo, Dept Forest Sci, BR-13418900 Piracicaba, SP, Brazil UNESP Univ Estadual Paulista, Biosci Inst, Dept Biochem & Microbiol, BR-13506900 Rio Claro, SP, Brazil