Publication Date:
2013-08-29
Description:
Plant cell-wall arabinoxylans have a complex structure that requires the action of a pool of debranching (arabinofuranosidases) and depolymerizing enzymes (endo-xylanase). Two Aspergillus nidulans strains over-secreting endo-xylanase and arabinofuranosidase were inoculated in defined 2% maltose-minimum medium resulting in the simultaneously production of these enzymes. To study the synergistic hydrolysis was used arabinoxylan with 41% of arabinose and 59% of xylose residues. Thus, it was adopted different approaches to arabinoxylan hydrolysis using immobilized arabinofuranosidase and endo-xylanase: (i) endo-xylanase immobilized on glyoxyl agarose; (ii) arabinofuranosidase immobilized on glyoxyl agarose; (T 1 ) hydrolysis of arabinoxylan with arabinofuranosidase immobilized on glyoxyl agarose for debranching, followed by a second hydrolysis with endo-xylanase immobilized on glyoxyl agarose; (T 2 ) hydrolysis using (i) and (ii) simultaneously; and (T 3 ) hydrolysis of arabinoxylan with endo-xylanase and arabinofuranosidase co-immobilized on glyoxyl agarose. It was concluded that arabinoxylan hydrolysis using two derivatives simultaneously (T 2 ) showed greater hydrolytic efficiency and consequently a higher products yield. However, the hydrolysis with multi-enzymatic derivative (T 3 ) results in direct release of xylose and arabinose from a complex substrate as arabinoxylan, which is a great advantage as biotechnological application of this derivative, especially regarding the application of biofuels, since these monosaccharides are readily assimilable for fermentation and ethanol production.
Print ISSN:
0021-924X
Electronic ISSN:
1756-2651
Topics:
Biology
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Chemistry and Pharmacology
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