Co-immobilization of fungal endo-xylanase and α-L-arabinofuranosidase in glyoxyl agarose for improved hydrolysis of arabinoxylan

• Published in: Journal of biochemistry (Tokyo) 2013-09, Vol.154 (3), p.275-280
• Main Authors: Damásio, André Ricardo de Lima, Pessela, Benevides C, da Silva, Tony Márcio, Guimarães, Luis Henrique Souza, Jorge, João Atílio, Guisán, Jose Manuel, Polizeli, Maria de Lourdes T M
• Format: Article
• Language: English
• Subjects: Arabinose - chemistry; Aspergillus nidulans; Aspergillus nidulans - chemistry; Aspergillus nidulans - enzymology; Culture Media; Endo-1,4-beta Xylanases - chemistry; Endo-1,4-beta Xylanases - isolation & purification; Fermentation; Fungal Proteins - chemistry; Fungal Proteins - isolation & purification; Glycoside Hydrolases - chemistry; Glycoside Hydrolases - isolation & purification; Glyoxylates - chemistry; Hydrogen-Ion Concentration; Hydrolysis; Immobilized Proteins - chemistry; Immobilized Proteins - isolation & purification; Kinetics; Sepharose - chemistry; Substrate Specificity; Temperature; Xylans - chemistry; Xylose - chemistry
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvt053

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; (T1) hydrolysis of arabinoxylan with arabinofuranosidase immobilized on glyoxyl agarose for debranching, followed by a second hydrolysis with endo-xylanase immobilized on glyoxyl agarose; (T2) hydrolysis using (i) and (ii) simultaneously; and (T3) hydrolysis of arabinoxylan with endo-xylanase and arabinofuranosidase co-immobilized on glyoxyl agarose. It was concluded that arabinoxylan hydrolysis using two derivatives simultaneously (T2) showed greater hydrolytic efficiency and consequently a higher products yield. However, the hydrolysis with multi-enzymatic derivative (T3) 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.