硅藻土固定中性脂肪酶的制备及其性质

以硅藻土为载体,采用吸附法,对脂肪酶进行固定化,研究了固定化条件对固定化脂肪酶的催化活性的影响,得到最佳的固定化条件：给酶量为33374U/g,固定化温度为35℃,pH值为7.5,时间为4h,此时固定化酶的活力约为5833U/g载体。固定化酶的热稳定性较游离酶有了很大的提高,其在80℃以下能保持80%以上的酶活,而游离酶60℃残余酶活仅为5%。最适反应温度和最适pH值也分别由游离酶的40℃上升至50℃和由7上升到7.5。对固定化中的中性脂肪酶在生物柴油合成中的应用也进行了初步研究。

Preparation and properties of neutrophil lipase immobilized by diatomine

The lipase was immobilized on the carrier diatomite with absorption activity.The effect of catalysis of immobilized lipase was studied.The optimal immobilizing condition was follow： the lipase quantity for 33374U/g,temperature 35℃,pH 7.5,treating for 4h.The preparation of immobilized enzyme was obtained.Its activity is approximately 5833U/g（carrier）.Optimum reactive temperature and pH of immobilized enzyme increased from free 40℃ to 50℃,and from 7 to 7.5,respectively.Thermal stability of immobilized enzyme was greatly improved.Its residual activity maintained more than 80% of initial activity after incubated at 80℃ for 1h,while free lipase residual activity only 5% at 60℃ after treated 1h.There was no change of acidic stability between free and immobilized enzymes.The potentiality of immobilized lipase to produce biodiesel from some oils was studied preliminarily.