【作者】 王秀国；

【导师】 朱鲁生；

【作者基本信息】 山东农业大学 ， 农药学， 2006， 硕士

【摘要】 本文以莠去津作为主要的研究对象,对莠去津的气相色谱测定方法,莠去津降解酶的提取,固定化酶的制备以及降解酶和固定化酶的特性进行了研究,并对降解酶和固定化酶在消除生产废水中的莠去津的应用前景进行了初步的探讨。主要内容如下:1.介绍了莠去津的理化性质、国内外应用概况,以及由于其广泛应用所带来的环境污染问题;在对前人工作总结分析的基础上,对莠去津在环境介质中的残留动态、降解代谢、生态毒理、污染治理措施以及生物修复技术-酶的固定化进行了全面系统的综述,进而提出了作者要研究的问题。2.分别测定了降解菌HB-5的无细胞培养液、细胞粗酶提取液等对莠去津的降解能力,从而对莠去津降解酶进行定位。研究证明,对莠去津的降解主要是胞内酶在起作用。从高效降解菌HB-5中提取到的降解酶,在不含有莠去津的培养基中连续转接7次,会逐渐丧失对莠去津的降解代谢活性,由此判断该降解酶不是组成酶,而是诱导酶。3.初步研究了从高效降解细菌HB-5(Arthrobacter)中提取的降解酶的分离条件及降解酶对莠去津的降解性能。以牛血清白蛋白为标准蛋白测得粗提酶中可溶性蛋白含量为0.65 mg·mL-1;该酶在pH 8.0～pH 9.5之间,酶活力均能保持在最高酶活力的89%以上,降解莠去津的最适pH为8.5;在25℃～45℃的温度范围内能保持较好的降解活性,最适温度为35℃;进一步研究发现,该酶具有较好的热稳定性和pH稳定性,暴露在温度30℃～40℃,pH 6.0～pH 9.0的条件下2h仍能保持较高的酶活力;该酶与底物莠去津结合力强,对莠去津具有较好的降解效果,其米氏常数Km为0.3459mmol·L-1,Vmax为0.7518μmol·mg-1·min-1。4.研究了降解酶对其他三氮苯类除草剂的降解能力。结果表明,降解酶除了对莠去津具有较高的降解能力外,对三氮苯类除草剂扑草净和西玛津也具有一定的降解代谢能力,尤其对西玛津表现出类似于莠去津的降解活性。5.研究了降解酶的固定化方法。选取包埋剂海藻酸钠浓度为2.0%、3.0%、3.5%、4.0%,固定剂CaCl2浓度为2.0%、3.0%、4.0%、5.0%以及更多还原

【Abstract】 In this dissertation, taking atrazine as a primary model pollutant, its GC analytical method, extraction of its degrading enzyme, immobilization of degrading enzyme and degradative characteristics of its degrading enzyme and immobilized enzyme, were studied systematically. Furthermore, application of atrazine degrading enzyme and immobilized enzyme to degrade atrazine in atrazine wastewater was studied preliminarily. The results could be summarized as follows:1. The situation of application, pollution and mobility in environment, ecological toxicological characteristics and pollutant management of atrazine, which had been applied extensively all over the world and recently in China, was introduced and accordingly the issues that would be investigated was presented by the author.2. The degradation of atrazine in free-cells supernatants of culture medium, pieces of cell wall and crude cell extracts were studied. The results showed that there were no detectable degradation in free-cells supernatants of culture medium and pieces of cell wall; but no detectable atrazine in crude cell extracts, which demonstrated that atrazine degrading enzyme located inside the cell of the isolated strain HB-5, which had been identified as Arthrobacter sp.. The atrazine degrading enzyme would loss its most activity when the strain was continuously transferred for 7 times under the condition of non-inducement. The results showed that this enzyme was also an inducible one.3. Degradative characteristics of degrading enzyme,which was extracted更多还原