A GH115 alpha-glucuronidase from Schizophyllum commune contributes to the synergistic enzymatic deconstruction of softwood glucuronoarabinoxylan

Background: Lignocellulosic biomass from softwood represents a valuable resource for the production of biofuels and bio-based materials as alternatives to traditional pulp and paper products. Hemicelluloses constitute an extremely heterogeneous fraction of the plant cell wall, as their molecular structures involve multiple monosaccharide components, glycosidic linkages, and decoration patterns. The complete enzymatic hydrolysis of wood hemicelluloses into monosaccharides is therefore a complex biochemical process that requires the activities of multiple degradative enzymes with complementary activities tailored to the structural features of a particular substrate. Glucuronoarabinoxylan (GAX) is a major hemicellulose component in softwood, and its structural complexity requires more enzyme specificities to achieve complete hydrolysis compared to glucuronoxylans from hardwood and arabinoxylans from grasses. Results: We report the characterisation of a recombinant α-glucuronidase (Agu115) from Schizophyllum commune capable of removing (4-O-methyl)-glucuronic acid ((Me)GlcA) residues from polymeric and oligomeric xylan. The enzyme is required for the complete deconstruction of spruce glucuronoarabinoxylan (GAX) and acts synergistically with other xylan-degrading enzymes, specifically a xylanase (Xyn10C), an α-l-arabinofuranosidase (AbfA), and a β-xylosidase (XynB). Each enzyme in this mixture showed varying degrees of potentiation by the other activities, likely due to increased physical access to their respective target monosaccharides. The exo-acting Agu115 and AbfA were unable to remove all of their respective target side chain decorations from GAX, but their specific activity was significantly boosted by the addition of the endo-Xyn10C xylanase. We demonstrate that the proposed enzymatic cocktail (Agu115 with AbfA, Xyn10C and XynB) achieved almost complete conversion of GAX to arabinofuranose (Araf), xylopyranose (Xylp), and MeGlcA monosaccharides. Addition of Agu115 to the enzymatic cocktail contributes specifically to 25 % of the conversion. However, traces of residual oligosaccharides resistant to this combination of enzymes were still present after deconstruction, due to steric hindrances to enzyme access to the substrate. Conclusions: Our GH115 α-glucuronidase is capable of finely tailoring the molecular structure of softwood GAX, and contributes to the almost complete saccharification of GAX in synergy with other exo- and endo-xylan-acting enzymes. This has great relevance for the cost-efficient production of biofuels from softwood lignocellulose.Lauren S. McKee, Hampus Sunner, George E. Anasontzis, Guillermo Toriz, Paul Gatenholm, Vincent Bulone, Francisco Vilaplana and Lisbeth Olsso

Data for: Hydrophobic Agave Fructans for Sustained Drug Delivery to the Human Colon (RAW)

NMR, FTIR, XPS, SEC, DSC, HPL

Data for: Hydrophobic Agave Fructans for Sustained Drug Delivery to the Human Colon (Processed)

Processed Dat

Data for: Hydrophobic Agave Fructans for Sustained Drug Delivery to the Human Colon (Processed)

Processed DataTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Data for: Hydrophobic Agave Fructans for Sustained Drug Delivery to the Human Colon (RAW)

NMR, FTIR, XPS, SEC, DSC, HPLCTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Inulin surfactants for drug delivery

[No abstract available

Inulin surfactants for drug delivery

[No abstract available

Lignin-polypropylene composites. II. Plasma modification of kraft lignin and particulate polypropylene

Indulin kraft lignin and polypropylene were subjected to plasma treatments in a rotating electrodeless plasma reactor at 13.56 MHz radio frequency, with the goal of improving the strength properties of the composites made from these materials. It was shown that efficient surface modification could be achieved by these plasma treatments, avoiding long reaction times and large volumes of reactants for modification by conventional wet chemistry. SiCl4-plasma treatments of lignin at 100 and 200 W resulted in silicon implantation in the range of 4-10% that depended on the treatment time. However, the effect of power in the treatments was minimal, given that changes in silicon implantation were not observed for changes in this parameter. SiCl4-plasma treatment of polypropylene at 80 W, 1 and 10 min, resulted in silicon implantation in the order of 10-15%, for the two different treatment times, showing that low power and short treatment times were sufficient to significantly alter the polypropylene surface. However at high power (250 W), the longer treatment time of polypropylene apparently led to formation of oligohalosilanes. Other plasma treatments in the rotating reactor such as plasma-induced copolymerization of acryloyl chloride on both lignin and polypropylene, and plasma-state polymerization of acryloyl chloride on polypropylene under pulsing conditions, resulted in thin film depositions. Evaluation of composites from these treated materials is described in the next contribution (Part III) from this series