Study on the Immobilization of Saccharifying Enzyme by Magnetic Chitosan Microspheres

Saccharifying enzyme was immobilized by absorption-cross-linking method with magnetic chitosan microspheres as carriers.The influencing factors including enzyme concentration,the addition level of glutaraldehyde,cross-linking temperature,and cross-linking time etc.were investigated and the enzymatic properties of the immobilized enzyme were studied.The results showed that the optimum immobilization conditions were as follows: 8 mL enzyme solution(its concentration was 0.5 mg/mL) used,addition of 4 mL 1 % glutaraldehyde solution,cross linking temperature was at 45 ℃,and cross-linking time was 4 h.The thermal stability and pH stability of the immobilized enzyme was better than that of free enzyme and 58 % enzyme activity preserved even after continuous use of immobilized enzyme for five times.