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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Improvement of fungal arabinofuranosidase thermal stability by reversible immobilization

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Author(s):
de Lima Damasio, Andre Ricardo [1] ; Pessela, Benevides C. [2] ; Segato, Fernando [3] ; Prade, Rolf Alexander [3] ; Manuel Guisan, Jose [4] ; Polizeli, Maria de Lourdes T. M. [5]
Total Authors: 6
Affiliation:
[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Bioquim & Imunol, BR-14040901 Ribeirao Preto, SP - Brazil
[2] CSIC, CIAL, Inst Ciencias Alimentac, Dept Biotecnol & Microbiol Alimentos, E-28049 Madrid - Spain
[3] Oklahoma State Univ, Dept Microbiol & Mol Genet, Stillwater, OK 74078 - USA
[4] CSIC, Inst Catalisis & Petr Quim, Dept Biocatalisis, Madrid 28049 - Spain
[5] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Process Biochemistry; v. 47, n. 12, p. 2411-2417, DEC 2012.
Web of Science Citations: 7
Abstract

A gene encoding a-L-arabinofuranosidase (abfA) from Aspergillus niveus was identified, cloned, and successfully expressed in Aspergillus nidulans. Based on amino acid sequence comparison, the 88.6 kDa enzyme could be assigned to the GH family 51. The characterization of the purified recombinant AbfA revealed that the enzyme was active at a limited pH range (pH 4.0-5.0) and an optimum temperature of 70 degrees C. The AbfA was able to hydrolyze arabinoxylan, xylan from birchwood, debranched arabinan, and 4-nitrophenyl arabinofuranoside. Synergistic reactions using both AbfA and endoxylanase were also assessed. The highest degree of synergy was obtained after the sequential treatment of the substrate with endoxylanase, followed by AbfA, which was observed to release noticeably more reducing sugars than that of either enzyme acting individually. The immobilization of AbfA was performed via ionic adsorption onto various supports: agarose activated by polyethyleneimine polymers, cyanogen bromide activated Sepharose, DEAE-Sepharose, and Sepharose-Q The Sepharose-Q derivative remained fully active at pH 5 after 360 min at 60 degrees C, whereas the free AbfA was inactivated after 60 min. A synergistic effect of arabinoxylan hydrolysis by AbfA immobilized in Sepharose-Q and endoxylanase immobilized in glyoxyl agarose was also observed. The stabilization of arabinofuranosidases using immobilization tools is a novel and interesting topic. (C) 2012 Elsevier Ltd. All rights reserved. (AU)