膨化稻壳的结构表征及固定化α-淀粉酶的研究

Structural characterization of puffed rice husk and its immobilization ofα-amylase

文章以实验室制备的膨化稻壳作为吸附载体,进行α-淀粉酶的固定化实验研究。对制备的膨化稻壳进行表征分析,结果表明稻壳膨化后结构更加疏松,—COO—和—OH等活性基团大量暴露,比表面积增大128%、孔容增加18%、平均孔径减小29%。通过正交试验得到优化固定化条件为:酶质量浓度1.0 mg/mL,海藻酸钠质量分数1.6%,膨化稻壳加量0.15 g,戊二醛体积分数0.4%,在此条件下固定化效率为95.7%。固定化酶的最适温度为70℃,最适pH值为6.0;固定化酶在进行6次循环使用后其相对酶活仍达53.85%,各方面性能均优于游离酶。

In this paper,puffed rice husk was prepared and used as adsorption carriers to immobilizeα-amylase.The properties and microstructure of puffed rice husk were characterized.The results showed that the puffed rice husk was porous with the active groups of-COO-and-OH exposed in large quantities.The specific surface area was increased 128%,pore volume increased 18%and average pore diameter decreased 29%,respectively.The optimal immobilization conditions were determined using orthogonal test as follows:the concentration of enzyme was 1.0 mg/mL,the mass fraction of sodium alginate was 1.6%,the volume fraction of glutaraldehyde was 0.4%,the dosage of puffed rice husk was 0.15 g,respectively.Under this condition,the enzyme activity recovery rate can reach 95.7%.The optimum reaction temperature and pH value were 70℃and 6.0.The enzyme activity was 53.85%after repeated operation for six times.It was superior to free enzyme in all aspects.