壳聚糖固定化德氏根霉脂肪酶的研究

Immobilization conditions of lipase from Rhizopus delemar

研究了壳聚糖吸附和戊二醛交联对脂肪酶固定化条件 ,在室温条件下将 0 .4 g酶粉溶于pH 6 .0缓冲液中 ,加入 10g壳聚糖 ,摇匀 ,再加入浓度为 0 .6 %戊二醛交联 6h ,得到固定化酶 ,酶活力回收率约为 5 4.2 %。固定化酶的半失活温度比游离酶的高 ,半失活温度由游离酶的 4 7℃提高到 10 0℃ ,最适反应温度由 4 0℃上升至 80℃ ,最适pH由 6下降到 5 .5 ,固定化酶K′m值由游离酶的Km 5 0mg/mL增加到 5 6mg/mL。该固定化脂肪酶用于酯的合成 ;在 80℃条件下经过 10批次连续水解植物油反应 ,固定化酶的活力仍保持在 82 .6 %以上。

Lipase was adsorbed on chitosan and crosslinked with glutaraldehyde. The immobilization conditions were studied. 10g chitosan was added to the suspension solution of 0.4g lipase at pH 6.0. Glutaraldehyde (0.6%) was used and immobilized lipase was obtained after 6 hours at the room temperature. In comparison with the free enzyme, the temperature to loss a half activity of the immobilized enzyme was increased from 47℃ to 100℃,the optimum temperature and optimum pH were shifted from 40℃ to 80℃ and from 6 to 5.5, respectively. The Km and K′m value of immobilized enzyme were 50 mg/ml and 56 mg/ml, respectively. The immobilized lipase was exploitative to use in hydrolysis of vegetable oil and synthesis of some esters. The immobilized enzyme activity remained activity of 82.6% after ten repeated batches of hydrolyzation of oil.