摘要
合成优良的漆酶固定化载体有利于其进一步应用。通过将磁性纳米颗粒包埋在苯胺的聚合物中形成磁性Fe_3O_4/聚苯胺纳米纤维,作为漆酶固定化载体。透射电镜和红外图谱分别显示了载体的形态结构特征。不同比例的Fe_3O_4与苯胺对载体结构没有明显影响,但会影响酶的负载量。合成载体最大酶负载量为210 mg/g,固定漆酶后的载体导电性能发生变化。固定化漆酶最适pH从4偏移到3.5,在酸性pH范围保持较高的酶活性,最适温度为60℃;在50℃下孵育240 min,能保持约50%的酶活性,于4℃下保存30 d能保持约60%的酶活性;重复使用8次后还能保留70%的酶活性;结果证实了磁性Fe_3O_4/聚苯胺纳米纤维成功合成,对酶有较高的负载量。随着Fe_3O_4的比例增加,载体对漆酶的负载量却减少;漆酶与载体间存在有一定电子交流。固定化漆酶的最适pH向酸性偏移可能和聚苯胺的导电性有关,合成载体显示出良好的热稳定性、储存稳定性和重复使用稳定性,表明磁性Fe_3O_4/聚苯胺纳米纤维是一种优良的酶固定化载体,可以实现酶的高效固定化。
It is the key to prepare a perfect carrier for enzyme immobilization for increasing enzyme loading, efficient use and reducing the cost of enzyme application. Magnetical polyaniline nanocomposite was synthesized via mixing aniline solution and Fe3O4 nanoparticles and used as laecase immobilization carrier. The successful synthesis was confirmed by the results of TEM and FT-IR. Different proportions of Fe3O4 and aniline had no significant effect on the structure of the carrier, but the enzyme loading was affected. The maximum loading of the synthetic carrier was 210 mg/g, and the conductive properties of carrier were changed after the lacease was immobilized on it. The optimum reaction pH and temperature for the immobilized laccase were 3.5 and 60℃, respectively. A slight shift of optimal pH was observed. Immobilized laccase kept 50% its activity after incubation at 50℃ for 240 min, and 60% of its activity after incubation at 4℃ for 30 d. Over a period of repeated operation, immobilized lacease still remained about 70% after 8 cycles. With the increase of the proportion of Fe3O4, the loading of the carrier reduced, and there was a certain electron exchange between laccase and the carrier. The immobilized laccase can be simply recovered from the reaction solution by a magnet. Immobilized laccase onto Fe3O4/polyaniline nanofiber shows high stabilities, easy recovery, and reuse capabilities, which demonstrated that Fe3O4/polyaniline nanofiber is a kind of perfect carrier for enzyme immobilization.
作者
刘友勋
王耀坤
闫明阳
黄娟
LIU You-xun WANG Yao-kun YAN Ming-yang HUANG Juan(School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang 45300)
出处
《生物技术通报》
CAS
CSCD
北大核心
2017年第3期205-212,共8页
Biotechnology Bulletin
基金
国家自然科学基金项目(U1304302)
河南省教育厅科学技术研究重点项目(12B180030)
关键词
磁性纳米颗粒
聚苯胺
漆酶
固定化
magnetic nanoparticle
polyaniline
laccase
immobilization
