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A β-1,3-xylan was prepared by sodium hydroxide extraction from seaweeds of Bryopsis maxima and Caulerpa sp. The seaweed xylan obtained contains xylose residues only and β-1,3-linkage was characterized by the method of 13C-NMR spectroscopy and methylation analysis. A strain of Aspergillus terreus A-07 isolated from soil produced an endo-β-1,3-xylanase, decomposing β-1,3-xylan to D-xylose and D-xylooligosaccharides. Six different xylanases in the culture filtrate of A. terreus A-07 have been found and purified to homogeneity from 40- to 95-fold by ammonium sulfate fractionation, SP-Sephadex C-25 ion exchange chromatography, Biogel P-100 gel filtration, and isoelectric focusing. Each of the purified enzymes gave a single band on polyacrylamide disc gel electrophoresis, indicating that all of the purified β-1,3-xylanases were electrophoretically homogeneous.The six kinds of purified enzymes on SDS polyacrylamide gel electrophoresis indicated that two of the β-1,3-xylanases have molecular weights of 11,000, an...

A purified extracellular endo β-1, 3-xylanase (EC 3.2.1.32) from an isolated strain, Aspergillus reus A-07, was found to hydrolyze 1, 3-xylosyl linkages only. When rhodymenan (β-1, 4 and β-1, 3-linked xylan) was hydrolyzed by β-1, 3-xylanase (EF-6), four β-1, 4-linked xylooligosaccharide ictions were produced. The main product was β-1, 4-xylotriose, with trace amounts of other β-1, 4-ked xylooligosaccharides. Successive degradation by β-1, 4-xylosidase of the β-1, 4-looligosaccharides that were produced from hydrolysis of β-1, 3-xylanase on rhodymenan yielded ly xylose as the final product. We compared the action pattern of this enzyme with that of an extracellular endo β-1, 4-lanase (EC 3.2.1.8) of Streptomyces. From a mixture of products of β-1, 4-xylanase hydrolysis on adymenan, an isomeric xylotriose was isolated by charcoal chromatography after treating with β-1, 4-xylosidase. The structure of this isomeric xylotriose was elucidated by methylation analysis and susceptibility to β-1, 4-xylanase, β-1, 3-xylanase, and β-1, 4-xylosidase. The obtained isomeric lotriose was identified as 3-O-β-xylopyranosyl-4-O-β-D-xylopyranosyl-D-xylose (XI→3X1→4X). It has a melting point of 224-225°C and [α]20D(c=1, H20)= -46°.

A purified extracellular endo β-1,3-xylanase (EC 3.2.1.32) from an isolated strain, Aspergillus terreus A-07, was found to hydrolyze 1,3-xylosyl linkages only. When rhodymenan (β-1,4 and β-1.3-linked xylan) was hydrolyzed by β-1,3-xylanase (EF-6), four β-1,4-linked xylooligosaccharide fractions were produced. The main product was β-1,4-xylotriose, with trace amounts of other β-1,4-linked xylooligosaccharides. Successive degradation by β-l,4-xylosidase of the β,4-xylooligosaccharides that were produced from hydrolysis of β-1,3-xylanase on rhodymenan yielded only xylose as the final product.We compared the action pattern of this enzyme with that of an extracellular endo β-l,4-xylanase (EC 3.2.1.8) of Streptomyces. From a mixture of products of β-1,4-xylanase hydrolysis on rhodymenan, an isomeric xylotriose was isolated by charcoal chromatography after treating with β-1.4-xylosidase. The structure of this isomeric xylotriose was elucidated by methylation analysis and its susceptibility to β-1,4-xylanase, β-1...