真菌漆酶在树脂D380上的固定及固定化漆酶的性质

Immobilization of fungal laccase on resin D380 and its property

为寻求一种廉价高效的漆酶固定化方法,以树脂D380为载体、戊二醛为交联剂,结合吸附法和交联法固定真菌漆酶,并研究固定化漆酶的性质。最优固定化条件:1 g载体在20 mL 0.7%的戊二醛溶液中交联2 h后,加入2 mL稀释酶液和5 mL pH为4的醋酸-醋酸钠缓冲溶液,在25℃下吸附反应6 h,最终获得的酶活回收率为65.94%。固定化漆酶的最适温度为20℃,最适pH为4,在4℃下保存14 d仍保持约80%的酶活力。自由漆酶和固定化漆酶的Km值分别为1.207mmol/L和1.616 mmol/L,说明固定后漆酶对底物的亲和力有所下降。

In order to seek a cheap and efficient way for immobilization of laccase, resin D380 as support and glutaraldehyde （GLU） as cross-linking agent were employed for immobilization of fungal laccase combining adsorption and cross-linking methods, and the properties of the immobilized laccase were also studied. The optimum conditions of the immobilization are as follows： after cross-linking for 2 h with 20 mL GLU of 0.7% , 1 g support were conducted in 2 mL diluent laccase solution and 5 mL HAC-NaAC buffer solution （pH = 4） to ad- sorb the laccase and react for 6 h at 25 ℃. The recovery of enzyme activity attained finally was 65.94%. The op- timum temperature and pH of the immobilized laecase were 20 ℃ and 4, respectively, and about 80% enzyme activity was still hold after preservation at 4 ℃ for 14 days. Michaeils constant of free and immobilized enzymes of 1. 207 mmol/L and 1. 616 mmol/L indicated that the affinity of immobilized enzyme to substrate was declined.