Partial Purification and Characterization of Inulinase Produced from a local isolate of Aspergillus niger J3

Abstract

Inulinase was produced from local isolate of Aspergillus niger J3. The inulinase was purified by two steps included precipitation by amonium sulphate at (30-80) % sa-turation and gel filtration on sephadex G100. The final purification folds and the yield of the enzyme were 3.15 times and 28.24%, respectively. The purified enzyme has the following characteristics: The optimum pH of the enzyme activity was 5.5. The enzyme was most stable at pH (4.5 - 6). The optimum temperature for its activity was 45c. The enzyme retained its original activity when incubates at (30-55) c for 20 minutes. Mercury chloride inhibited the enzyme completely at concentration of 10mM, cupper sulphate and calisium chloride inhibited the enzyme at concentrations of 85% and 7% respectively. It was revealed that the enzyme had the efficiency to hydrolyze 87% of 5% inulin solution when treated at 45c for 120 min.