含铊废水处理菌株脱铊基因解析和基因工程菌的构建

Drinking and water supply security has already been posed a serious threat by the scattered elements of thallium pollution at potable water sources caused by development and utilization of mineral resource containing thallium. It had been demonstrated that treating waste water containing thallium using microbiology was feasible, which had lots of advantages including well removal effect and low cost. Several exclusive strains for removal thallium had been screened out from the bioreactor which had been used to treat waste water containing thallium for a long time. Based on the previous studies, Research on screening strains resistant and production conditions would be carried out. The project would realizing size and location of thallium removal coding region in DNA molecules, and analyzing thallium removal gene, in order to probe into thallium mechanism of bacterial strain at the genetic level. Genetic engineering technology would be used to clone genes of heavy mental resistance. These genes would be constructed in a carrier construction by connecting enzyme on the gene integration platform system, in order to get a genetic engineering strain, together with identifying recombinant plasmid of purpose size. Influence factors of treating waste water containing thallium using the engineering bacterium and its genetic stability would be researched in the project. The conditions of treating waste water containing thallium using the genetic engineering strain would be optimized. Research on treating waste water containing thallium would be carried out on the base of using domestic sewage as nutrient. Research on explaining removal mechanism of the strain would be of great scientific significance. The project also has important significance for solving thallium pollution of the source of drinking water caused by development and utilization of mineral resource containing thallium. It also has great significance for studying safety , application and dissemination of the freshman engineering bacterium.

含铊矿产资源开采和利用引发的水源地分散毒害元素铊污染已对饮用/供水安全构成严重威胁。前期研究表明，采用微生物方法对含铊废水进行处理，具有处理成本低、效果好等优势。从处理含铊废水的生物反应器内污泥中筛选出几株对铊具有良好专属性的菌株。本项目拟在前期研究的基础上，对菌株开展抗性和生长条件研究，通过Southern印迹杂交技术了解菌株DNA分子脱铊编码区的大小和位置，解析脱铊基因，从基因水平探讨菌株脱铊机理。克隆出抗重金属基因，利用基因整合平台将脱铊和抗金属基因通过连接酶构建在一个载体中，得到基因工程菌，并对目的大小重组质粒进行鉴定。探讨基因工程菌脱铊条件和工程菌的稳定性。以生活污水为营养物对含铊废水进行处理研究。本研究对于阐释菌株脱铊机理具有重要的科学意义，基因工程菌的构建对于解决含铊矿产资源开发利用带来的饮用水水源铊污染问题和新生工程菌安全性及推广应用研究都具有重要意义。

本项目开展了除铊菌的生理生化特性、基因特性、菌株抗性和环境影响条件、除铊机理、生物反应器再启动和固定化工程类菌处理重金属等多个方面开展了研究，本项目顺利完成了研究计划，并取得了一系列有特色的创新性成果。研究表明具有特异性基因异化亚硫酸盐还原酶基因的除铊菌对于毒害元素铊具有较好的耐受性，适应环境条件能力强；除铊菌对其他不同金属耐受性不同，此外碳源种类也影响其硫还原性能；硫酸盐还原途径、胞外物吸附和电子传递三种机制协同作用发挥了菌株除铊主要作用；再启动效率高，分子生物学分析方法表明反应器内启动后，系统内存在包括产酸克雷伯杆菌、阴沟肠杆菌、鞘氨醇单胞菌属细菌、帕尼帕特假单胞菌和弗氏拧檬酸杆菌在内的多种微生物；混凝强化法可有效完善生物除铊反应体系，固定化方法对于进一步优化含铊废水处理技术体系具有重要的理论和现实意义。本项目的开展对于预防和阻控含铊酸性废水对饮用水水源地污染，保障供水安全具有重要意义，可为更科学地进行污染风险评估提供科学依据，同时也可为这些敏感区域相关行业的发展和污染阻控提供参考。