锰超氧化物歧化酶对六价铬微生物还原修复的影响及机制研究

Cr(VI)微生物还原是去除废水中Cr(Ⅵ)最有前景的修复方法。氧化压力和以沉淀形式存在的Cr(III)导致Cr(VI)还原菌株活性减小，限制了Cr(VI)还原菌株的实际应用。锰超氧化物歧化酶（Mn-SOD）能减小氧化压力、络合Cr(III)、阻止Cr(III)氧化。鉴于对Cr(Ⅵ)微生物还原修复的迫切需求，本课题拟研究Mn-SOD高效表达对Cr(VI)微生物还原修复的影响及机制，包括构建Mn-SOD高效表达的Cr(Ⅵ)还原菌株；研究Mn-SOD高效表达菌株的Cr(VI)还原特性，明确Mn-SOD对Cr(Ⅵ)还原菌株活性的影响；分析Mn-SOD与Cr(III)之间的作用关系，Mn-SOD在Cr(III)重新氧化过程中的作用，及pH调控对Mn-SOD结构及Cr(III)固定的影响，从而揭示Mn-SOD调控机制。本项目的研究将对开发具有实际应用价值的Cr(VI)还原菌株提供理论依据和参考。

Cr(Ⅵ) microbial reduction is the best efficient method for the removal of Cr(Ⅵ) in industrial effluents. Oxidative stress and Cr(III) in the form of precipitates result in decrease in the activity of Cr(Ⅵ) reducing strain, which limits the practical application of Cr(VI) reducing strain. Manganese superoxide dismutase can elimit oxidative stress, complex Cr(III) and prevent Cr(III) from reoxidation. In view of needpress for Cr(Ⅵ) reduction remediation of microorganism, This project intends to study the effect and mechanism of overexpression of manganese superoxide dismutase on Cr(Ⅵ) microbial reduction remediation. The research includes the construction of Cr(VI) reducing strain with Mn-SOD overexpressing，the illumination of Mn-SOD effect on reducing strain activity by investigating Cr(VI) reduction features of Cr(VI) reducing strain with Mn-SOD overexpressing, the revelation of the possible regulation mechanism by analyzing the interrelationship of Mn-SOD and Cr(III), the function of Mn-SOD in the process of Cr(III) reoxidation, and the regulation of pH for Mn-SOD structure and Cr(III) immobility. This research can provide theoretical basis and reference for developing the strain with practical application value.