earticle

영어

A xylanase bacteria, isolated from Waste Mushroom bed of Agaricus bisporus in Sukseong-myeon, Buyeo-gun, Chungcheongnam-do, was used to produce an xylanase in shaker buffle flask cultures containing oat spelt xylans. This strain was screen onto xylan agar congo-red plate by the xylanolysis method. The phylogenetic analysis using 16S rRNA sequence data showed that Bacillus subtilisstrain 55 had the highest homology (99.0%) with Bacillus subtilisand it was named Bacillus subtilisstrain 55. Bacteria grows and activity maximum during 2 days. The xylanase enzyme was purified by ammonium sulfate precipitation (50~80%), gel filtration on sephacryl S-300, and ion exchange chromatography on DEAE sepharose FF. The molecular weight determined by SDS-PAGE method. Enzyme size was 44kDa. The optimal pH of the xylanase activity was pH 7, and stability pH 6. The optimal temperature for the xylanase activity and stability was showed same temperature at 50℃. The purified xylnase had Kmvalue and Vmax of 20㎎/㎖ and 2500μM/min respectively. The enzyme was active on oat spelt xylan, beechwood xylan and little activity on starch substrate specificity. Enzyme activity was enhanced by Fe2+and Mn2+and strongly inhibited by Hg+.