磁性松香基高分子固定化交联脂肪酶聚集体的制备及性质研究

Preparation and property of immobilized cross-linked enzyme aggregates on magnetic rosin-based polymer

制备了磁性松香基高分子固定化交联脂肪酶聚集体(固定化CLEAs-L)。研究制备条件对固定化CLEAs-L活性的影响,并研究了固定化CLEAs-L的结构与性质。结果表明,固定化CLEAs-L的最佳制备条件为:沉淀剂无水乙醇用量30%,脂肪酶质量浓度4 g/L,一次交联反应中添加0. 3%的戊二醛,交联反应2 h,二次交联反应中添加1%的戊二醛,交联脂肪酶聚集体与载体的质量比2. 5∶1。在最佳条件下,固定化CLEAs-L的酶活回收率为86. 52%,固定化CLEAs-L的最适温度和pH分别为45℃和7. 0。与游离脂肪酶、CLEAs-L相比,固定化CLEAs-L热稳定性和储存稳定性明显提高;重复操作6次后,固定化CLEAs-L的酶活回收率仍保持在60. 00%以上。

The immobilized cross-linked enzyme aggregates (CLEAs-L) on magnetic rosin-based polymer were prepared. The effects of preparation conditions on the activity of immobilized CLEAs-L were evaluated. Moreover,the properties and structures of immobilized CLEAs-L were investigated.The results showed that the optimal preparation conditions were obtained as follows: dosage of precipitant (absolute ethanol) 30%,lipase mass concentration 4 g/L,glutaraldehyde dosage 0. 3% in the first cross-linking reaction,reaction time 2 h,glutaraldehyde dosage 1% in the second cross-linking reaction,and the mass ratio of CLEAs-L to carrier 2. 5∶ 1. Under these conditions,the recovery rate of enzyme activity was 86. 52%,and the optimal temperature and pH of immobilized CLEAs-L were 45 ℃and 7. 0 respectively. The thermal and storage stability of immobilized CLEAs-L were improved remarkably compared with the free lipase and CLEAs-L. After six batch reactions,the recovery rate of enzyme activity of immobilized CLEAs-L was still above 60. 00%.