离子液体再生纤维素微球共固定漆酶-介体体系及对吲哚的降解

co-Immobilized Laccase-mediator with Cellulose Microspheres Reconstituted from Ionic Liquid for Indole Degradation

利用离子液体溶解纤维素混合体系固定化介体2,2'-联氨-双-3-乙基苯并噻唑啉-6-磺酸(ABTS),介体分子被封装于具有三维网络通道结构的纤维素微球中.利用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)等表征了微球的形貌、结构和组成.利用多巴胺自聚合作用将漆酶固定在封装介体的纤维素微球上,实现了漆酶与介体的共固定.由于固定化ABTS的介导作用,制备的球状共固定漆酶-ABTS催化剂,对吲哚的降解率达到99%以上,并呈现出相比于游离漆酶更高的耐热性和耐酸碱性.球状共固定漆酶-ABTS催化剂可重复用于吲哚的生物降解,连续循环使用9次,吲哚的降解率保持在89.6%.

An innovative method of preparing immobilized laccase-mediator system was established by immobilizing Trametes versicolor laccase and 2,2＇-azino-bis（ 3-ethylbenzothiazoline-6-sulfonic acid）（ ABTS）on cellulose microspheres simultaneously. The mediator ABTS was mixed with ionic liquid cellulose solution and was encapsulated during the process of cellulose regeneration. The as-prepared cellulose-ABTS microspheres（ Ce/ABTS） with network pore structure were characterized by scanning electron microscopy（ SEM）,X-ray diffraction（ XRD） and Fourier transform infrared spectrometer（ FTIR）. Then laccase was immobilized on Ce/ABTS by dopamine self-polymerization to obtain co-immobilized laccase-ABTS system（ Ce/ABTS@ Do/Lac）. The method realized the co-immobilization of laccase and mediator facilely and effectively. The Ce/ABTS@ Do/Lac was used in the enzymatic degradation of indole,and the degradation rate was up to 99%. As compared with the free laccase,the Ce/ABTS@ Do/Lac showed higher p H stability and thermostability. Benefited from the mediation effect of the immobilized ABTS,the Ce/ABTS @ Do/Lac still retained considerably catalytic activity for indole degradation after 9 cycling runs. The recovery of both laccase and mediator is promising to reduce the cost for the application of laccase in wastewater treatment and might be helpful to cut down the secondary pollution from free mediator. The Ce/ABTS @ Do/Lac must have a great potential in large-scale application for organic wastewater treatment.