NITRILE HYDRATASE FROM A THERMOPHILIC BACILLUS-SMITHII

A novel thermophilic Bacillus smithii strain SC-J05-1, isolated from a hot spring, had the ability of hydrating nitrile to form amide, The n itrile hydratase was purified to homogeneity from the microbial cells of SC-J05-1 and was characterized. The enzyme was a 130-kDa protein co mposed of two different subunits (25.3 kDa and 26.8 kDa) and contained cobalt ions. This enzyme had the optimal temperature of 40 degrees C and was stable up to 50 degrees C, The optimal pH was in the alkaline region higher than pH 10.