PURIFICATION AND SOME PROPERTIES OF BETA-MANNANASE FROM BACILLUS SP

beta-Mannanase produced by Bacillus sp. W-2, isolated from decayed commercial konjak cake, was purified from the culture supernatant by (NH4)(2)SO4 precipitation, adsorption to konjak gel, and column chromatography with DEAE-cellulose, Sephadex G-100 and Sephacryl S-200. Its molecular size was estimated by SDS-PAGE as 40 kDa, and by gel filtration as 36 kDa. The enzyme was most active at pH 7 and 70 degrees C and was stable for at least 1 h between pH 5 and 10 and below 60 degrees C. Its activity was completely inhibited by Hg2+. The enzyme hydrolysed galactomannan better than glucomannan and mainly produced mannose and mannobiose.