Xylanase and beta-xylosidase from Penicillium janczewskii: Purification, characterization and hydrolysis of substrates

Autor(es)

Fanchini Terrasan, Cesar Rafael ; Manuel Guisan, Jose ; Carmona, Eleonora Cano

• Tipo de documento: Artigo Científico
• Fonte: ELECTRONIC JOURNAL OF BIOTECHNOLOGY; v. 23, p. 54-62, SEP 2016.
• Citações Web of Science: 12

Resumo

Background: Xylanases and beta-D-xylosidases are the most important enzymes responsible for the degradation of xylan, the second main constituent of plant cell walls. Results: In this study, the main extracellular xylanase (XYL I) and beta-xylosidase (BXYL I) from the fungus Penicillium janczewskii were purified, characterized and applied for the hydrolysis of different substrates. Their molecular weights under denaturing and non-denaturing conditions were, respectively, 30.4 and 23.6 kDa for XYL I, and 100 and 200 kDa for BXYL I, indicating that the latter is homodimeric. XYL I is highly glycosylated (78%) with optimal activity in pH 6.0 at 65 degrees C, while BXYL I presented lower sugar content (10.5%) and optimal activity in pH 5.0 at 75 degrees C. The half-lives of XYL I at 55, 60 and 65 degrees C were 125, 16 and 6 min, respectively. At 60 degrees C, BXYL I retained almost 100% of the activity after 6 h. NH4+, Na+, DTT and beta-mercaptoethanol stimulated XYL I, while activation of BXYL I was not observed. Interestingly, XYL I was only partially inhibited by Hg2+, while BXYL I was completely inhibited. Xylobiose, xylotriose and larger xylooligosaccharides were the main products from xylan hydrolysis by XYL I. BXYL I hydrolyzed xylobiose and larger xylooligosaccharides with no activity against xylans. Conclusion: The enzymes act synergistically in the degradation of xylans, and present industrial characteristics especially in relation to optimal activity at high temperatures, prolonged stability of BXYL I at 60 degrees C, and stability of XYL I in wide pH range. (C) 2016 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 07/08640-8 - Xilanases, b-xilosidases de Penicillium janczewskii: purificação, caracterização e aplicação no branqueamento da polpa celulósica e para ração animal
• Beneficiário: César Rafael Fanchini Terrasan
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 10/16582-0 - Purificação, propriedades e aplicação de enzimas xilanolíticas produzidas por Penicillium janczewskii
• Beneficiário: Eleonora Cano Carmona
• Modalidade de apoio: Auxílio à Pesquisa - Regular