Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

Full text
Author(s):
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]
Total Authors: 8
Affiliation:
[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
Total Affiliations: 4
Document type: Journal article
Source: JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC; v. 89, p. 93-101, MAY 2013.
Web of Science Citations: 13
Abstract

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)