Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/22172
Título: | A novel xylan degrading β-D-xylosidase: purification and biochemical characterization |
Autor(es): | Michelin, Michele Peixoto-Nogueira, Simone C. Silva, Tony M. Jorge, João A. Terenzi, Héctor F. Teixeira, J. A. Polizeli, Maria de Lourdes T. M. |
Palavras-chave: | Aspergillus ochraceus b-xylosidase Purification Xylan β-xylosidase |
Data: | 2012 |
Editora: | Kluwer |
Revista: | World Journal of Microbiology and Biotechnology |
Resumo(s): | Aspergillus ochraceus, a thermotolerant fungus isolated in Brazil from decomposing materials, produced an extracellular b-xylosidase that was purified using DEAE-cellulose ion exchange chromatography, Sephadex G-100 and Biogel P-60 gel filtration. b-xylosidase is a glycoprotein (39 % carbohydrate content) and has a molecular mass of 137 kDa by SDS-PAGE, with optimal temperature and pH at 70 C and 3.0–5.5, respectively.b-xylosidase was stable in acidic pH (3.0–6.0) and 70 C for 1 h. The enzyme was activated by 5 mM MnCl2 (28 %)and MgCl2 (20 %) salts. The b-xylosidase produced by A. ochraceus preferentially hydrolyzed p-nitrophenyl-b- D-xylopyranoside, exhibiting apparent Km and Vmax values of 0.66 mM and 39 U (mg protein)-1 respectively, and to a lesser extent p-nitrophenyl-b-D-glucopyranoside. The enzyme was able to hydrolyze xylan from different sources,suggesting a novel b-D-xylosidase that degrades xylan. HPLC analysis revealed xylans of different compositions which allowed explaining the differences in specificity observed by b-xylosidase. TLC confirmed the capacity. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/22172 |
DOI: | 10.1007/s11274-012-1128-9 |
ISSN: | 1573-0972 0959-3993 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series |
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fulltext.pdf | 357,1 kB | Adobe PDF | Ver/Abrir |