Purification and Characterization of Porphyran-Decomposing Enzymes from Arthrobacter sp. S-22

Porphyran-decomposing enzymes were purified from the culture fluid of Arthrobacter sp. S-22, by ammonium sulfate precipitation, CM-Sephadex C-50, DEAE-Sephadex A-50, Toyopearl HW-55F and Butyl-Toyopearl 650M column chromatography. Each of the purified two enzymes (enzyme I and II) showed a single band, with molecular weights of 28, 000 and 42, 000 on SDS-polyacrylamide gel electrophoresis, respectively. Porphyran-decomposing enzyme I was stable at pH 6-8 and showed maximal activity at pH 6, 60°C. Porphyran-decomposing enzyme II was stable at pH 4.5-7.5 and showed maximal activity at pH 5, 50°C Both enzymes showed a substrate specificity on porphy-ran. Enzyme I produced tetraoligosaccharide from porphyran, and enzyme II produced dioligogosac-charide.