凹凸棒土固定脂肪酶及其在催化菜籽油转酯反应中的应用

Immobilization of lipase with attapulgite and its application in rape oil transesterification

采用吸附法对来源于Staphylococcus aureusJH的脂肪酶进行了固定化。以凹凸棒土作为载体系统研究了固定化条件对固定化效率及固定化酶转酯活力的影响。结果表明最适加酶量、缓冲液pH和吸附时间分别为0.35 g/g、8.0和3 h,在上述优化条件下固定化酶的转酯活力为465.5 U/g,而所用的游离酶只有较低转酯活性。利用该固定化酶催化菜籽油转酯反应生产生物柴油时,叔丁醇为适宜的反应介质,其最适添加量为0.8 mL/g;适宜的酶量、加水量和反应温度分别为40.0 U/g、油质量的的1.2%和40℃。按甲醇/油摩尔为3.5的比例在优化反应条件下,反应12 h后甲酯产率达96.0%;固定化脂肪酶具有较好的操作稳定性,反应160批次时,相对酶活力为78.4%。

Lipase from Staphylococcus aureus JH is immobilized by physical adsorption with attapulgite selected as the support.The effects of immobilization conditions on the immobilization efficiency and transesterification activity of the immobilized lipase are systematically studied.The results show that the optimal enzyme amount,pH,and adsorption time are 0.35 g/g,8.0,and 3 h,respectively.Under optimal conditions the transesterification activity of the immobilized enzyme can be 465.5 U/g,whereas the free enzyme do...