Immobilization and biochemical properties of a beta-xylosidase activated by glucose/xylose from Aspergillus niger USP-67 with transxylosylation activity

Autor(es)

Benassi, Vivian Machado ^[1] ; da Silva, Tony Marcio ^[2] ; Costa Pessela, Benevides ^[3] ; Manuel Guisan, Jose ^[4] ; Mateo, Cesar ^[4] ; Lima, Matheus Sanita ^[2] ; Jorge, Joao Atilio ^[2] ; Polizeli, Maria de Lourdes T. M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Bioquim & Imunol, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[3] CIAL CSIC, Inst Ciencias Alimentac, Dept Biotecnol & Microbiol Alimentos, Madrid 28049 - Spain

^[4] Inst Catalisis & Petroleoquim CSIC, Dept Biocatalisis, Madrid 28049 - Spain

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC; v. 89, p. 93-101, MAY 2013.
• Citações Web of Science: 13

Resumo

beta-Xylosidases have important applications in many biotechnological processes. In this context, the aim of this work was the purification, immobilization and characterization of a beta-xylosidase produced by a new isolate of Aspergillus niger USP-67. beta-Xylosidase was produced on static conditions in liquid Benassi medium supplemented with xylan birchwood, initial pH 3.0, for 6 days, at 30 degrees C. The enzyme was purified on DEAE-Sepharose followed of Superdex (TM) 200, and the molecular mass of the beta-xylosidase was estimated to be 100 kDa, with 90% similarly to the beta-xylosidase xInD from A. niger (gi 146230215 accession), using MS sequencing. The enzyme was immobilized on DEAE-Sepharose, Polyethyleneimine (PEI)-Sepharose, Q-Sepharose, CM-Sepharose, Sulphopropil-Sepharose and MANAE-agarose, but the best result was obtained with PEI-Sepharose, which presented 94% of immobilization yield. Moreover, this derivative was more thermal stable than the soluble enzyme and other supports, which presented a half-life of about 50 min, at 65 degrees C. The enzyme immobilized on PEI-Sepharose had an optimum pH more acidic (around 4.5) than the purified enzyme (pH 5.5). Metal ions inhibited the soluble enzyme activity more than the immobilized form; however, Zn2+ increased the activity of the immobilized enzyme in 29%. The specific activity of the immobilized enzyme corresponded to 98.15 U/mg, but the soluble enzyme was 77.96 U/mg. Furthermore, the K-M and K-cat values for the purified enzyme with p-nitrophenyl-xylopyranoside as substrate were 0.654 mM and 58.87 s(-1) and for the immobilized enzyme the values were 0.587 mM and 88.95 s(-1), respectively. The purified enzyme efficiently hydrolyzed xylooligosaccharides until xylose, but other xylooligosaccharides (X2-X6) were formed, suggesting transxylosylation action. The immobilized beta-xylosidase of A. niger was not inhibited by xylose (100 mM) and glucose (200 mM), what confers to this enzyme a potential application in biotechnological processes. (C) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/52322-3 - Bioprospecção de fungos filamentosos produtores de holoenzimas com aplicação em biorefinaria
• Beneficiário: Maria de Lourdes Teixeira de Moraes Polizeli
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular