Abstract: Inulinase from Aspergillus ficuum SK004 was immobilized on cotton cloth activated with p-toluenesulfonyl chloride(tosyl chloride). The immobilization conditions were optimized and the results showed that the optimal amount of dry pyridinewas 10ml to each gram of cotton and the ratio of tosyl (g) /pyridine (ml) was 1g:1ml. The optimal coupling pH was found to be4.5 and ionic strength was 0.2mol/L. 80U enzyme was immobilized onto each gram of cotton cloth. The highest enzyme activityyield achieved 83.60% through orthogonal test. At these conditions, immobilized enzyme reacting with 250g/L inulin for 1.5h gained28.21% FOS (fructose oligosaccharide) analyzed by HPLC. Among different fibrous materials tested, the charpie cotton clothshowed the highest immobilized enzyme activity.

Key words: inulinase, immobilization, tosyl chloride, cotton cloth