水凝胶固定化漆酶微反应器的构建及其酶促降解染料废水的研究

To develop highly efficient dyeing wastewater treatment approaches is an important task in water pollution control. Laccase can degrade many types of organic pollutants under mild conditions, showing great application potential in textile wastewater treatment. However, the water solubility and the low stability of the laccase limit its practical application in wastewater treatment. Immobilization is a key strategy for the repeatable and continuous application of laccase. In this project, we propose to use laccase-mediator systems to initiate in situ assembly of chitosan-based hydrogels for immobilization of laccase, aiming at: (1) to develop new immobilization strategies that allow the laccase to build a suitable host for itself, without unwanted configuration change or activity loss which is usually unavoidable in the currently available immobilization methods, (2) to dig new types of low-cost and eco-friendly mediators for laccase, which are expecting to overcome the bottleneck in the application of laccase due to the toxicity and the high cost of the currently available mediators, (3) to elucidate the expression mechanisms of the immobilized laccase through the analysis of the structure-activity relationship in the oxidative degradation of dyes by the immobilized laccase-mediator system, as well as the substrate selectivity and responses to environmental stimuli, and finally, 4) to provide theoretical background and technique support for the recyclable application of the immobilized laccase microreactors.

发展新型高效的染料废水处理技术是水污染控制领域的一个重要任务。漆酶能在温和的条件下氧化降解多种类型的有机污染物，已在印染废水处理领域显示出良好的应用前景。然而，漆酶的水溶性和不稳定性限制了其在实际废水处理中的应用。酶的固定化是实现酶重复连续使用和稳定性改善的有效手段。本项目拟通过漆酶-介体体系引发原位组装制备壳聚糖基水凝胶固定化漆酶微反应器，旨在构建使酶能够自主选择固定化空间的方法，从而避免现有固定化技术中因酶被动适应载体空间所致构型的变化乃至活性的降低；开发适用于漆酶体系的新型廉价高效且环境友好的中间介体，以克服现有漆酶介体毒性大、成本高的应用困境；从染料和介体分子的微观结构入手，探讨固定化漆酶氧化降解染料的结构-活性关系，结合底物选择性和环境刺激响应，阐释固定化漆酶的酶活表达作用机制；最终通过染料废水小试实验为固定化漆酶微反应器重复连续处理染料废水提供理论依据和技术支持。

漆酶在温和的条件下可氧化降解多种类型有机污染物，已在印染废水处理领域显示出良好的应用前景。然而，漆酶的水溶性和不稳定性限制了其在实际废水处理中的应用。酶的固定化是实现酶重复连续使用和稳定性改善的有效手段。本项目以壳聚糖为预聚物，利用丙烯酰胺为单体，通过漆酶-双酮体系引发丙烯酰胺与壳聚糖的共聚，成功原位合成了壳聚糖基水凝胶固定化漆酶微反应器；在此基础上进一步做了器型化处理，通过把自聚溶液滴入铜溶液得到了大小均匀、尺寸可控的固定化漆酶-介体微球微反应器；通过产物分析和活性粒子测定，判断双酮在固定化漆酶-介体微球反应器的形成和酶促转化中起到了类似介体的重要作用；结合底物选择性和环境刺激响应，阐释了固定化漆酶的酶活表达作用机制，为固定化漆酶微反应器在染料废水处理中的应用提供理论依据和技术支持。经过三年的努力，我们超额完成了项目预定的目标。通过该课题的实施，已培养出硕士生4名，博士生1名。他们在课题的开展中得到了良好的训练，获得了不少科研经验，也取得了一些科研成果。已毕业4名硕士研究生的学位论文均获得答辩委员会的好评，其中有2名同学获得了“国家奖学金”，1名同学获得“校长特别奖学金”，3名同学获得“优秀研究生”称号。已正式发表SCI论文14篇，该项目的研究成果申请国家发明专利和美国发明专利各1项，已获授权国家发明专利1项。