(1. 南華大學(xué) 公共衛(wèi)生學(xué)院，衡陽 421001；
2. 南華大學(xué) 化學(xué)化工學(xué)院，衡陽 421001；
3. 南華大學(xué) 衡陽醫(yī)學(xué)院，衡陽 421001)
摘 要: 本文提取擴(kuò)增硫酸鹽還原菌中關(guān)鍵還原基因dsrA，將其轉(zhuǎn)入耐輻射奇球菌(DR)中，構(gòu)建基因工程菌Deino-dsrA。考察溶液pH值、菌劑量、鈾初始濃度、富集時間等因素對基因工程菌Deino-dsrA還原富集性能的影響。采用掃描電鏡和電子能譜(SEM-EDS)以及傅里葉變換紅外光譜儀(FTIR)表征該基因工程菌，分析鈾富集前后菌體表面形貌結(jié)構(gòu)、元素和基團(tuán)的變化，探明其還原富集鈾(Ⅵ)的行為。結(jié)果表明：在溶液pH值為5、菌劑所占比例為33%、鈾初始濃度為30 mg/L、富集時間為60 min時，該基因工程菌還原富集鈾(Ⅵ)的效果最佳。基因工程菌對鈾的富集過程符合準(zhǔn)二級反應(yīng)動力學(xué)模型及Langmuir等溫線模型。基因工程菌Deino-dsrA富集率(92.45%)相比野生型DR富集率(72.02%)顯著提升。該基因工程菌以其耐輻射、高還原富集、環(huán)境友好等多重優(yōu)勢，將在含鈾廢水的治理領(lǐng)域具有可觀的應(yīng)用前景。
關(guān)鍵字: 耐輻射奇球菌；還原基因dsrA；鈾；還原富集
（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
