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Wageningen, Netherlands

Klyosov A.A.,Moscow State University | Dotsenko G.S.,RAS A.N. Bach Institute of Biochemistry | Hinz S.W.A.,Dyadic Nederland BV | Sinitsyn A.P.,RAS A.N. Bach Institute of Biochemistry
Carbohydrate Research | Year: 2012

Statistical modeling was applied for describing structural features of β-(1→4)-d-galactomannans. According to the model suggested theoretical ratios of limiting degrees of locust bean, tara gum and guar gum galactomannan conversions by two β-(1→4)-mannanases of different origin (Myceliophthora thermophila and Trichoderma reesei) were calculated. Then the enzymes were tested for enzymatic hydrolysis of three considered galactomannans. Experimentally observed results were compared with theoretically calculated ones. It was shown that T. reesei β-mannanase attacks sequences of four and more unsubstituted mannopyranosyl residues in a row, while M. thermophila β-mannanase is a more specific enzyme and attacks sequences of five and more mannopyranosyl residues in a row. Considered statistical model and approach allows to characterize both galactomannan structures and enzyme requirements for regions of unsubstituted mannose residues for substrate hydrolysis. © 2012 Elsevier Ltd. All rights reserved. Source

Koutaniemi S.,University of Helsinki | van Gool M.P.,Wageningen University | van Gool M.P.,Cargill Inc. | Juvonen M.,University of Helsinki | And 4 more authors.
Journal of Biotechnology | Year: 2013

Mass spectrometric analysis was used to compare the roles of two acetyl esterases (AE, carbohydrate esterase family CE16) and three acetyl xylan esterases (AXE, families CE1 and CE5) in deacetylation of natural substrates, neutral (linear) and 4-O-methyl glucuronic acid (MeGlcA) substituted xylooligosaccharides (XOS). AEs were similarly restricted in their action and apparently removed in most cases only one acetyl group from the non-reducing end of XOS, acting as exo-deacetylases. In contrast, AXEs completely deacetylated longer neutral XOS but had difficulties with the shorter ones. Complete deacetylation of neutral XOS was obtained after the combined action of AEs and AXEs. MeGlcA substituents partially restricted the action of both types of esterases and the remaining acidic XOS were mainly substituted with one MeGlcA and one acetyl group, supposedly on the same xylopyranosyl residue. These resisting structures were degraded to great extent only after inclusion of α-glucuronidase, which acted with the esterases in a synergistic manner. When used together with xylan backbone degrading endoxylanase and β-xylosidase, both AE and AXE enhanced the hydrolysis of complex XOS equally. © 2013 Elsevier B.V. Source

Pouvreau L.,Wageningen University | Jonathan M.C.,Wageningen University | Kabel M.A.,Wageningen University | Hinz S.W.A.,Dyadic Nederland BV | And 2 more authors.
Enzyme and Microbial Technology | Year: 2011

Two novel acetyl xylan esterases, Axe2 and Axe3, from Chrysosporium lucknowense (C1), belonging to the carbohydrate esterase families 5 and 1, respectively, were purified and biochemically characterized. Axe2 and Axe3 are able to hydrolyze acetyl groups both from simple acetylated xylo-oligosaccharides and complex non-soluble acetylglucuronoxylan. Both enzymes performed optimally at pH 7.0 and 40°C.Axe2 has a clear preference for acetylated xylo-oligosaccharides (AcXOS) with a high degree of substitution and Axe3 does not show such preference. Axe3 has a preference for large AcXOS (DP 9-12) when compared to smaller AcXOS (especially DP 4-7) while for Axe2 the size of the oligomer is irrelevant. Even though there is difference in substrate affinity towards acetylated xylooligosaccharides from Eucalyptus wood, the final hydrolysis products are the same for Axe2 and Axe3: xylo-oligosaccharides containing one acetyl group located at the non-reducing xylose residue remain as examined using MALDI-TOF MS, CE-LIF and the application of an endo-xylanase (GH 10). © 2011 Elsevier Inc. Source

Dyadic Nederland B.V. | Date: 2015-09-09

The present invention provides a new fungal production system comprising a fungal host strain of

van Gool M.P.,Wageningen University | van Muiswinkel G.C.J.,Dyadic Nederland BV | Hinz S.W.A.,Dyadic Nederland BV | Schols H.A.,Wageningen University | And 2 more authors.
Enzyme and Microbial Technology | Year: 2013

Two novel GH11 endo-xylanases from Myceliophthora thermophila C1 (C1), Xyl7 and Xyl8, were purified and the influence of solubility and molecular structure of various xylans on their efficiency was investigated. Both endo-xylanases were hindered by a high degree of substitution of a xylan. The two GH11 xylanases released different products from the xylans, in which Xyl7 displayed a degradation product composition closer to GH10 xylanases. A correlation of the degradation product composition with a specific residue at position 163 in the amino acid sequence of Xyl8 is suggested: tyrosine in Xyl8; valine in Xyl7. This is confirmed with examples of various endo-xylanases reported in literature.The C1 GH11 xylanases were more efficient on self-associated xylan compared to C1 GH10 endo-xylanases and they released more small xylooligomers from these xylans. This is contrary to the general assumption that GH10 xylanases degrade xylans to a higher degree than GH11 xylanases. © 2013 Elsevier Inc. Source

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