Abstract
β-1, 3-Xylanase was purified from the culture fluid of a marine bacterium, Vibrio sp. AX-4, by ammonium sulfate precipitation and successive column chromatographies. The final enzyme preparation appeared to be homogeneous on polyacrylamide gel electrophoresis. The enzyme had a molecular weight of 53, 000 daltons, a pI of 3.6, a pH optimum of 6.0 to 6.5, and was stable in a pH region from 4.5 to 10, and at temperatures below 40°C. The β-1, 3-Xylanase was an endo-type enzyme which degraded β-1, 3-xylan to yield xylose and xylooligosaccharides. The hydrolysis products from xylotriose were xylose and xylobiose. Xylotetraose was cleaved to xylose, xylotriose, and a small amount of xylobiose. The hydrolysis products from xylopentaose were mainly xylose and xylotetraose in addition to small amounts of xylobiose and xylotriose. The enzyme did not act on xylobiose, p-nitrophenyl-β-D-xyloside, and β-1, 4-xylan.
