(1. 南华大学 公共卫生学院，衡阳 421001；
2. 南华大学 化学化工学院，衡阳 421001；
3. 南华大学 衡阳医学院，衡阳 421001)
摘 要: 本文提取扩增硫酸盐还原菌中关键还原基因dsrA，将其转入耐辐射奇球菌(DR)中，构建基因工程菌Deino-dsrA。考察溶液pH值、菌剂量、铀初始浓度、富集时间等因素对基因工程菌Deino-dsrA还原富集性能的影响。采用扫描电镜和电子能谱(SEM-EDS)以及傅里叶变换红外光谱仪(FTIR)表征该基因工程菌，分析铀富集前后菌体表面形貌结构、元素和基团的变化，探明其还原富集铀(Ⅵ)的行为。结果表明：在溶液pH值为5、菌剂所占比例为33%、铀初始浓度为30 mg/L、富集时间为60 min时，该基因工程菌还原富集铀(Ⅵ)的效果最佳。基因工程菌对铀的富集过程符合准二级反应动力学模型及Langmuir等温线模型。基因工程菌Deino-dsrA富集率(92.45%)相比野生型DR富集率(72.02%)显著提升。该基因工程菌以其耐辐射、高还原富集、环境友好等多重优势，将在含铀废水的治理领域具有可观的应用前景。
关键字: 耐辐射奇球菌；还原基因dsrA；铀；还原富集
（1. School of Public Health, University of South China, Hengyang 421001, China;
2. School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China;
3. Hengyang Medical College, University of South China, Hengyang 421001, China）
Abstract:The key reduction gene dsrA was extracted from sulfate reducing bacteria, and it was transferred into Deinococcus radiodurans (DR) to construct the genetically engineered bacteria Deino-dsrA. The effects of solution pH, ratio of bacterial suspension, initial uranium concentration and enrichment time on the performance of the genetically engineered bacteria were investigated. Scanning electron microscopy, energy dispersive spectrometer (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphological structure of genetically engineered bacteria before and after uranium enrichment. The changes of elements and groups were analyzed, and the behavior of uranium(Ⅵ) enrichment was investigated. The results show that the genetically engineered bacteria has the best effect on the enrichment of uranium(Ⅵ) when the solution pH is 5, the ratio of bacterial suspension is 33%, the initial concentration of uranium is 30 mg/L, and the enrichment time is 60 min. The enrichment process of uranium by genetically engineered bacteria conforms to the pseudo-second-order reaction kinetic model and Langmuir isotherm model. The enrichment rate of Deino-dsrA (92.45%) is significantly higher than the wild-type deinococcus radiodurans (72.02%). The genetically engineered bacteria will have considerable application prospect in the environmental treatment of uranium wastewater due to its multiple advantages of radiation resistance, high reduction capacity and environmental friendliness.
Key words: deinococcus radiodurans; reduction gene dsrA; uranium; reduction enrichment
