γFe2O3凹土超顺磁性纳米复合材料固载猪胰脂肪酶

摘要

The porcine pancreatic lipase( PPL) was immobilized on superparamagnetic γ-Fe2O3-attapulgite nanocomposites ( γ-Fe2 O3-ATP ) . The γ-Fe2 O3-ATP was characterized with transmission election microscopy ( TEM ) , BET and VSM. The immobilization conditions and enzymatic properties of immobilized PPL were investigated. The results showed that the γ-Fe2 O3-ATP was mesoporous material,specific surface area was 102.63 m2/g,average pore diameter was 10.862 nm, and saturation magnetization was 8.915 emu/g. The optimal immobilization conditions were determined to be pH 6.0 and immobilization time was 4 h. The thermal stability of the immobilized enzyme was enhanced compared with the free enzyme. The residual activity was kept at 52% for 6 h, while that of the free enzyme was just 19%. The catalytic activity of immobilized enzyme was kept at 60% after 5 batch reactions. Enzymes supported on superparamagnetic γ-Fe2O3-ATP could be easily separated and reused.%以凹凸棒石黏土为原料，制备γ Fe2 O3凹土超顺磁性纳米复合材料（γ Fe2 O3 ATP ）作为猪胰脂肪酶（PPL）固定化的载体，利用透射电子显微镜（TEM）、N2吸附脱附等温图（BET）、振动试样磁强计（VSM）等对材料进行表征，同时对固定化条件和固定化酶的相关性质进行了研究。结果表明：制备的γ Fe2 O3 ATP是介孔材料，比表面积为.63 m2/g，平均孔径为.862 nm，饱和磁化强度为.915 emu/g，其作为载体能实现固定化酶与反应介质简单、快速分离回收和重复利用。在固定化时间为h及pH6.0时制备的固定化酶效果最佳；经过h高温保存后固定化酶可保留初始酶活的％，而游离酶仅保留初始酶活的％，同时固定化酶在重复使用次后酶活仍保留初始酶活的％。