Purification and some properties of endo-1,3-beta-D-xylanase from Pseudomonas sp. PT-5.

An endo-1,3-beta-D-xylanase (1,3-beta-D-xylan xylanohydrolase, EC 3.2.1.32) was purified from the culture fluid of Pseudomonas sp. PT-5 by ammonium sulfate fractionation, DEAE-Sepharose CL-6B, Toyopearl HW-50S, and Butyl-Toyopearl 650 M column chromatography. The purified enzyme gave a single band on polyacrylamide gel disc electrophoresis and its molecular weight was 35,000 by SDS-polyacrylamide gel electrophoresis. The enzyme was stable from pH 5.5 to 8.0 and had its maximum activity at pH 7.5. The enzyme rapidly reduced the viscosity of glycol beta-1,3-xylan solutions and produced xylose and xylooligosaccharides from seaweed beta-1,3-xylan. The enzyme activity was greatly inhibited by Hg2+, SDS, ethylenediamine tetraacetic acid (EDTA), and N-bromosuccinimide (NBS).