异噁草松降解酶的定位及酶学性质研究

摘要

对可降解异嗯草松的降解菌W2的降解酶进行定位试验,测得其细胞碎片悬浮液、胞外酶和胞内酶对异嗯草松的降解率分别为36.28％,8.71％和62.27％,因此确定降解异噁草松的主要活性物质位于降解菌细胞内,属于胞内酶.应用气相色谱法研究异嗯草松降解酶的酶学性质,结果表明:最佳酶促反应时间为60 min,最佳酶液添加量为0.3 mL,最适pH为7.5,最适反应温度为35℃,米氏常数Km=2.668 × 10-4 mmol/mL,最大反应速率Vmax=0.322×10-4 mmol/min.%The localization of clomazone-degrading enzyme from bacteria W2 was tested. It was observed that the degradation of clomazone by cell pieces, ectoenzyme and entoenzyme were 36.28%, 8.71% and 62.27%, respectively. The results showed that the active substances of clomazone-degrading were entoenzyme. Gas chromatogra-phy method was used to define the enzymatic properties. The optimum conditions for the enzyme were as follows: 60 min of reaction time, 0.3mL enzyme, pH7.5 and 35 ℃ . The kinetic constants were achieved. includingKm = 2.668×10-4 mmol/mL and Vmax=0.322×10-4 mmol/min.