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Water-soluble hemicelluloses were extracted from milled aspen wood (Populus tremula) employing microwave oven treatment at 180 degrees C for 10 min. The final pH of this extract was 3.5. From this extract oligo- and polysaccharides were isolated and subsequently fractionated by size-exclusion chromatography. The structures of the saccharides in three of the(More)
A beta-mannosidase was purified to homogeneity from the culture filtrate of Aspergillus niger. A specific activity of 500 nkat mg-1 and a 53-fold purification was achieved using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration. The isolated enzyme has an isoelectric point of 5.0 and appears to be a dimer composed of two(More)
The recent years have witnessed considerable developments in the interpretation of the three-dimensional structures of plant polysaccharide-degrading enzymes in the context of their functional specificity. A plethora of new structures of catalytic, carbohydrate-binding and protein-scaffolding modules involved in (hemi)cellulose catabolism has emerged in(More)
The microbial deconstruction of the plant cell wall is a key biological process that is of increasing importance with the development of a sustainable biofuel industry. The glycoside hydrolase families GH5 (PaMan5A) and GH26 (PaMan26A) endo-β-1,4-mannanases from the coprophilic ascomycete Podospora anserina contribute to the enzymatic degradation of(More)
beta-Mannanase (endo-1,4-beta-mannanase; mannan endo-1,4-beta-mannosidase; EC 3.2.1.78) catalyzes endo-wise hydrolysis of the backbone of mannan and heteromannans, including hemicellulose polysaccharides, which are among the major components of plant cell walls. The gene man1, which encodes beta-mannanase, of the filamentous fungus Trichoderma reesei was(More)
Water-soluble hemicellulose was extracted from corn fiber with microwave-assisted heat treatment. The effects of treatment temperature and initial pH of the aqueous extraction media were investigated regarding hemicellulose recovery and molecular mass of the isolated polysaccharides. In treatments carried out at neutral pH (simple water extraction), it has(More)
Endo-beta-1,4-D-mannanases (beta-mannanase; EC 3.2.1.78) are endohydrolases that participate in the degradation of hemicellulose, which is closely associated with cellulose in plant cell walls. The beta-mannanase from Trichoderma reesei (Man5A) is composed of an N-terminal catalytic module and a C-terminal carbohydrate-binding module (CBM). In order to(More)
Alpha-galactosidase (EC 3.2.1.22) and beta-mannosidase (EC 3.2.1.25) participate in the hydrolysis of complex plant saccharides such as galacto(gluco)mannans. Here we report on the cloning and characterization of genes encoding an alpha-galactosidase (AglC) and a beta-mannosidase (MndA) from Aspergillus niger. The aglC and mndA genes code for 747 and 931(More)
The enzymes needed for galactomannan hydrolysis, i.e., beta-mannanase, alpha-galactosidase and beta-mannosidase, were produced by the filamentous fungus Aspergillus niger. The beta-mannanase was purified to electrophoretic homogeneity in three steps using ammonium sulfate precipitation, anion-exchange chromatography and gel filtration. The purified enzyme(More)
The aim of this study was to investigate how physico-chemical properties of two dietary fibres, guar gum and pectin, affected weight gain, adiposity, lipid metabolism, short-chain fatty acid (SCFA) profiles and the gut microbiota in male Wistar rats fed either low- or high-fat diets for three weeks. Both pectin and guar gum reduced weight gain, adiposity,(More)