PURIFICATION AND CHARACTERIZATION OF A DI-D-FRUCTOFURANOSE-2',1-2,1'-DIANHYDRIDE PRODUCING ENZYME FROM STREPTOMYCES SP MCI-2524

An extracellular enzyme that produces di-D-fructofuranose 2',1;2,1'-dianhydride (difructose anhydride I = DFA I) from inulin was purified from the culture broth of Streptomyces sp. MCI-2524. The purification enhanced the specific activity 7-fold with an overall yield of 17%. The purified enzyme, when electrophoresed on a SDS polyacrylamide gel, gave a single band corresponding to a molecular weight of 36 kDa. Gel filtration chromatography gave a single peak that eluted at a position corresponding to 70 kDa. The enzyme was active from pH 3.0 to pH 9.0, and at temperatures up to 65-degrees-C. Maximal activity was observed at pH 6.0, at 55-degrees-C. The enzyme was inhibited by Cu2+.