Xylan

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Kristian E Frandsen - One of the best experts on this subject based on the ideXlab platform.

  • Lytic Xylan oxidases from wood-decay fungi unlock biomass degradation
    Nature Chemical Biology, 2018
    Co-Authors: Marie Couturier, Ana Villares, Céline Moreau, Bernard Cathala, Simon Ladevèze, Gerlind Sulzenbacher, Luisa Ciano, Mathieu Fanuel, Florence Chaspoul, Kristian E Frandsen
    Abstract:

    Wood biomass is the most abundant feedstock envisioned for the development of modern biorefineries. However, the cost-effective conversion of this form of biomass into commodity products is limited by its resistance to enzymatic degradation. Here we describe a new family of fungal lytic polysaccharide monooxygenases (LPMOs) prevalent among white-rot and brown-rot basidiomycetes that is active on Xylans—a recalcitrant polysaccharide abundant in wood biomass. Two AA14 LPMO members from the white-rot fungus Pycnoporus coccineus substantially increase the efficiency of wood saccharification through oxidative cleavage of highly refractory Xylan-coated cellulose fibers. The discovery of this unique enzyme activity advances our knowledge on the degradation of woody biomass in nature and offers an innovative solution for improving enzyme cocktails for biorefinery applications. A new type of fungal lytic polysaccharide monooxygenase (LPMO) catalyzes the oxidative degradation of Xylan components of cellulosic biomass and offers potential in wood biorefining.

  • lytic Xylan oxidases from wood decay fungi unlock biomass degradation
    Nature Chemical Biology, 2018
    Co-Authors: Marie Couturier, Ana Villares, Céline Moreau, Bernard Cathala, Simon Ladevèze, Gerlind Sulzenbacher, Luisa Ciano, Mathieu Fanuel, Florence Chaspoul, Kristian E Frandsen
    Abstract:

    Wood biomass is the most abundant feedstock envisioned for the development of modern biorefineries. However, the cost-effective conversion of this form of biomass into commodity products is limited by its resistance to enzymatic degradation. Here we describe a new family of fungal lytic polysaccharide monooxygenases (LPMOs) prevalent among white-rot and brown-rot basidiomycetes that is active on Xylans—a recalcitrant polysaccharide abundant in wood biomass. Two AA14 LPMO members from the white-rot fungus Pycnoporus coccineus substantially increase the efficiency of wood saccharification through oxidative cleavage of highly refractory Xylan-coated cellulose fibers. The discovery of this unique enzyme activity advances our knowledge on the degradation of woody biomass in nature and offers an innovative solution for improving enzyme cocktails for biorefinery applications.

Hendrik Arie Schols - One of the best experts on this subject based on the ideXlab platform.

  • effect of pretreatment severity on Xylan solubility and enzymatic breakdown of the remaining cellulose from wheat straw
    Bioresource Technology, 2007
    Co-Authors: Mirjam A Kabel, Jan Zeevalking, A G J Voragen, Hendrik Arie Schols
    Abstract:

    Abstract The effect of process conditions used for wheat straw pretreatments on the liquor- and residue-composition was studied. Hereto, the pretreatment conditions were expressed in a ‘combined severity R 0 ′ -factor’. The higher the combined severity factor ( R 0 ′ ) the more Xylan was released from the wheat straw, but the more Xylan decomposed and furfural formation occurred. The percentage of residual Xylan present after pretreatment appeared to be a good indicator concerning cellulose degradability or bio-ethanol production. Namely, cellulose degradation by using commercial enzymes was higher at higher severities corresponding to a lower amount of residual Xylan. The Xylan release and degradation was studied in more detail by using HPSEC and MALDI-TOF mass spectrometry. The more severe the treatment the more (acetylated) xylose oligomers with a DP lower than nine were analysed. The presence of (acetylated) Xylans with a DP of 9–25 increased slightly from low to medium severity. The quantification of the DP-distribution of the (acetylated) Xylans released proved to be a good tool to predict cellulose degradability.

  • Structural differences of Xylans affect their interaction with cellulose
    Carbohydrate Polymers, 2007
    Co-Authors: Mirjam A Kabel, Alphons G.j. Voragen, Hein Van Den Borne, Jean-paul Vincken, Hendrik Arie Schols
    Abstract:

    The affinity of Xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different Xylans to cellulose. Therefore, the adsorption of various Xylans to bacterial cellulose (BC) was studied. Also, the relationship between Xylan size and adsorption was analysed. BC was used as cellulosic material, because of its high specific surface area and homogeneous structure. In general, unsubstituted linear Xylan parts favoured adsorption to BC. Xylan affinity for BC was also related to Xylan size. The presence of arabinosyl and O-acetyl substituents to Xylan decreased the adsorption of Xylan to BC considerably. Removing substituents resulted in higher amounts of adsorbed material. Most likely, increasing the number of unsubstituted xylosyl residues induced the formation of Xylan?Xylan interactions, which contributed to adsorption to BC. Schematic models are proposed showing the adsorption of structurally different Xylans to BC. Keywords: Xylan; Bacterial cellulose; Adsorption; Affinity; Structural characteristics

  • Standard assays do not predict the efficiency of commercial cellulase preparations towards plant materials
    Biotechnology and Bioengineering, 2006
    Co-Authors: Mirjam A Kabel, Alphons G.j. Voragen, Marc J.e.c. Van Der Maarel, Gert Klip, Hendrik Arie Schols
    Abstract:

    Commercial cellulase preparations are potentially effective for processing biomass feedstocks in order to obtain bioethanol. In plant cell walls, cellulose fibrils occur in close association with Xylans (monocotyls) or xyloglucans (dicotyls). The enzymatic conversion of cellulose/Xylans is a complex process involving the concerted action of exo/endocellulases and cellobiases yielding glucose and Xylanases yielding xylooligomers and xylose. An overview of commonly measured cellulase-, cellobiase-, and Xylanase-activity, using respectively filter paper, cellobiose, and AZCL-dyed Xylan as a substrate of 14 commercially available enzyme preparations from several suppliers is presented. In addition to these standardized tests, the enzyme-efficiency of degrading native substrates was studied. Grass and wheat bran were fractionated into a water unsoluble fraction (WUS), which was free of oligosaccharides and starch. Additionally, cellulose- and Xylan-rich fractions were prepared by alkaline extraction of the WUS and were enzymatically digested. Hereby, the capability of cellulose and Xylan conversion of the commercial enzyme preparations tested was measured. The results obtained showed that there was a large difference in the performance of the fourteen enzyme samples. Comparing all results, it was concluded that the choice of an enzyme preparation is more dependent on the characteristics of the substrate rather than on standard enzyme-activities measured.

  • hydrothermally treated Xylan rich by products yield different classes of xylo oligosaccharides
    Carbohydrate Polymers, 2002
    Co-Authors: Mirjam A Kabel, Hendrik Arie Schols, Florbela Carvalheiro, Gil Garrote, E Avgerinos, E G Koukios, Juan Carlos Parajo, Francisco M Girio, Alphons G.j. Voragen
    Abstract:

    Four Xylan rich by-products, namely wheat bran, brewery's spent grain, corn cobs and Eucalyptus wood, were characterised and subjected to a mild hydrothermal treatment in order to release and degrade the Xylan from the starting materials. The chemical characterisation of the feedstock materials, with emphasis on the extracted Xylan fractions and using enzymatic degradation of these Xylans, resulted in rather detailed pictures of the Xylans present. Depending on the feedstock material studied, the Xylan present was substituted with arabinose, 4-O-methylglucuronic acid and acetyl groups. During the hydrothermal treatment, arabinose was rather easily removed from the Xylan-backbone (wheat bran, brewery's spent grain and corn cobs). The acetyl groups were partly released from the feedstocks, becoming available to catalyse the depolymerisation of the Xylan. Also, part of the uronic acids were released, mainly during the treatment of Eucalyptus wood. Due to the partial release of the substituents and cleavage of the Xylan by the treatment performed, a wide variety of xylo-oligosaccharides with different structural features corresponding to the Xylan-structure of the original feedstock were obtained. Xylo-oligosaccharides branched with arabinose were identified in the hydrolysate from brewery's spent grain, while in the hydrolysate of corn cobs and Eucalyptus wood xylo-oligosaccharides substituted with 4-O-methylglucuronic acid were present as well. Additionally, a series of partially acetylated (acidic) xylo-oligosaccharides was identified in the Eucalyptus wood hydrolysate.

Yanting Wang - One of the best experts on this subject based on the ideXlab platform.

  • arabinose substitution degree in Xylan positively affects lignocellulose enzymatic digestibility after various naoh h2so4 pretreatments in miscanthus
    Bioresource Technology, 2013
    Co-Authors: Fengcheng Li, Zhengdan Xu, Fen Tu, Shiguang Zhou, Yuanyuan Tu, Qing Li, Yan Chen, Wei Zhang, Yu Li, Yanting Wang
    Abstract:

    Abstract Xylans are the major hemicelluloses in grasses, but their effects on biomass saccharification remain unclear. In this study, we examined the 79 representative Miscanthus accessions that displayed a diverse cell wall composition and varied biomass digestibility. Correlation analysis showed that hemicelluloses level has a strong positive effect on lignocellulose enzymatic digestion after NaOH or H 2 SO 4 pretreatment. Characterization of the monosaccharide compositions in the KOH-extractable and non-KOH-extractable hemicelluloses indicated that arabinose substitution degree of Xylan is the key factor that positively affects biomass saccharification. The xylose/arabinose ratio after individual enzyme digestion revealed that the arabinose in Xylan is partially associated with cellulose in the amorphous regions, which negatively affects cellulose crystallinity for high biomass digestibility. The results provide insights into the mechanism of lignocellulose enzymatic digestion upon pretreatment, and also suggest a goal for the genetic modification of hemicelluloses towards the bioenergy crop breeding of Miscanthus and grasses.

  • Arabinose substitution degree in Xylan positively affects lignocellulose enzymatic digestibility after various NaOH/H2SO4 pretreatments in Miscanthus
    Bioresource Technology, 2013
    Co-Authors: Fengcheng Li, Shuangfeng Ren, Jianxiong Jiang, Wei Zhang, Yan Chen, Qing Li, Yanting Wang, Shizhong Li, Yuanyuan Tu, Qiwei Li, Zhengdan Xu, Hai-chun Jing, Lin Liu, Fasong Zhou, Shiguang Zhou, Jingping Qin, Fen Tu, Guosheng Xie, Yuan Li, Neal Gutterson
    Abstract:

    Xylans are the major hemicelluloses in grasses, but their effects on biomass saccharification remain unclear. In this study, we examined the 79 representative Miscanthus accessions that displayed a diverse cell wall composition and varied biomass digestibility. Correlation analysis showed that hemicelluloses level has a strong positive effect on lignocellulose enzymatic digestion after NaOH or H2SO4 pretreatment. Characterization of the monosaccharide compositions in the KOH-extractable and non-KOH-extractable hemicelluloses indicated that arabinose substitution degree of Xylan is the key factor that positively affects biomass saccharification. The xylose/arabinose ratio after individual enzyme digestion revealed that the arabinose in Xylan is partially associated with cellulose in the amorphous regions, which negatively affects cellulose crystallinity for high biomass digestibility. The results provide insights into the mechanism of lignocellulose enzymatic digestion upon pretreatment, and also suggest a goal for the genetic modification of hemicelluloses towards the bioenergy crop breeding of Miscanthus and grasses. © 2012 Elsevier Ltd.

Marie Couturier - One of the best experts on this subject based on the ideXlab platform.

  • Lytic Xylan oxidases from wood-decay fungi unlock biomass degradation
    Nature Chemical Biology, 2018
    Co-Authors: Marie Couturier, Ana Villares, Céline Moreau, Bernard Cathala, Simon Ladevèze, Gerlind Sulzenbacher, Luisa Ciano, Mathieu Fanuel, Florence Chaspoul, Kristian E Frandsen
    Abstract:

    Wood biomass is the most abundant feedstock envisioned for the development of modern biorefineries. However, the cost-effective conversion of this form of biomass into commodity products is limited by its resistance to enzymatic degradation. Here we describe a new family of fungal lytic polysaccharide monooxygenases (LPMOs) prevalent among white-rot and brown-rot basidiomycetes that is active on Xylans—a recalcitrant polysaccharide abundant in wood biomass. Two AA14 LPMO members from the white-rot fungus Pycnoporus coccineus substantially increase the efficiency of wood saccharification through oxidative cleavage of highly refractory Xylan-coated cellulose fibers. The discovery of this unique enzyme activity advances our knowledge on the degradation of woody biomass in nature and offers an innovative solution for improving enzyme cocktails for biorefinery applications. A new type of fungal lytic polysaccharide monooxygenase (LPMO) catalyzes the oxidative degradation of Xylan components of cellulosic biomass and offers potential in wood biorefining.

  • lytic Xylan oxidases from wood decay fungi unlock biomass degradation
    Nature Chemical Biology, 2018
    Co-Authors: Marie Couturier, Ana Villares, Céline Moreau, Bernard Cathala, Simon Ladevèze, Gerlind Sulzenbacher, Luisa Ciano, Mathieu Fanuel, Florence Chaspoul, Kristian E Frandsen
    Abstract:

    Wood biomass is the most abundant feedstock envisioned for the development of modern biorefineries. However, the cost-effective conversion of this form of biomass into commodity products is limited by its resistance to enzymatic degradation. Here we describe a new family of fungal lytic polysaccharide monooxygenases (LPMOs) prevalent among white-rot and brown-rot basidiomycetes that is active on Xylans—a recalcitrant polysaccharide abundant in wood biomass. Two AA14 LPMO members from the white-rot fungus Pycnoporus coccineus substantially increase the efficiency of wood saccharification through oxidative cleavage of highly refractory Xylan-coated cellulose fibers. The discovery of this unique enzyme activity advances our knowledge on the degradation of woody biomass in nature and offers an innovative solution for improving enzyme cocktails for biorefinery applications.

Fengcheng Li - One of the best experts on this subject based on the ideXlab platform.

  • arabinose substitution degree in Xylan positively affects lignocellulose enzymatic digestibility after various naoh h2so4 pretreatments in miscanthus
    Bioresource Technology, 2013
    Co-Authors: Fengcheng Li, Zhengdan Xu, Fen Tu, Shiguang Zhou, Yuanyuan Tu, Qing Li, Yan Chen, Wei Zhang, Yu Li, Yanting Wang
    Abstract:

    Abstract Xylans are the major hemicelluloses in grasses, but their effects on biomass saccharification remain unclear. In this study, we examined the 79 representative Miscanthus accessions that displayed a diverse cell wall composition and varied biomass digestibility. Correlation analysis showed that hemicelluloses level has a strong positive effect on lignocellulose enzymatic digestion after NaOH or H 2 SO 4 pretreatment. Characterization of the monosaccharide compositions in the KOH-extractable and non-KOH-extractable hemicelluloses indicated that arabinose substitution degree of Xylan is the key factor that positively affects biomass saccharification. The xylose/arabinose ratio after individual enzyme digestion revealed that the arabinose in Xylan is partially associated with cellulose in the amorphous regions, which negatively affects cellulose crystallinity for high biomass digestibility. The results provide insights into the mechanism of lignocellulose enzymatic digestion upon pretreatment, and also suggest a goal for the genetic modification of hemicelluloses towards the bioenergy crop breeding of Miscanthus and grasses.

  • Arabinose substitution degree in Xylan positively affects lignocellulose enzymatic digestibility after various NaOH/H2SO4 pretreatments in Miscanthus
    Bioresource Technology, 2013
    Co-Authors: Fengcheng Li, Shuangfeng Ren, Jianxiong Jiang, Wei Zhang, Yan Chen, Qing Li, Yanting Wang, Shizhong Li, Yuanyuan Tu, Qiwei Li, Zhengdan Xu, Hai-chun Jing, Lin Liu, Fasong Zhou, Shiguang Zhou, Jingping Qin, Fen Tu, Guosheng Xie, Yuan Li, Neal Gutterson
    Abstract:

    Xylans are the major hemicelluloses in grasses, but their effects on biomass saccharification remain unclear. In this study, we examined the 79 representative Miscanthus accessions that displayed a diverse cell wall composition and varied biomass digestibility. Correlation analysis showed that hemicelluloses level has a strong positive effect on lignocellulose enzymatic digestion after NaOH or H2SO4 pretreatment. Characterization of the monosaccharide compositions in the KOH-extractable and non-KOH-extractable hemicelluloses indicated that arabinose substitution degree of Xylan is the key factor that positively affects biomass saccharification. The xylose/arabinose ratio after individual enzyme digestion revealed that the arabinose in Xylan is partially associated with cellulose in the amorphous regions, which negatively affects cellulose crystallinity for high biomass digestibility. The results provide insights into the mechanism of lignocellulose enzymatic digestion upon pretreatment, and also suggest a goal for the genetic modification of hemicelluloses towards the bioenergy crop breeding of Miscanthus and grasses. © 2012 Elsevier Ltd.