| Cr6+生物可利用度检测的微生物全细胞传感器CB10的构建及其响应特征 |
| 摘要点击 1846 全文点击 1308 投稿时间：2012-06-28 修订日期：2012-08-16 |
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| 中文关键词 Cr6+ 生物可利用度 微生物全细胞传感器 特异性 温度 pH |
| 英文关键词 Cr6+ bioavailability microbial whole-cell biosensor specificity temperature pH |
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| 中文摘要 |
| 为实现重金属污染环境中Cr6+的生物可利用度评价,进而为Cr6+的污染治理提供可靠依据,本研究采用分子生物技术,以重金属广谱抗性菌株Cupriavidus metallidurans CH34的pMOL28质粒上铬抗性调控系统的启动子和调控蛋白基因为传感器调控元件,以北美萤火虫Photinus pyralis的萤火虫荧光素酶基因luc为报告基因构建了一种可对Cr6+生物可利用度进行检测的微生物全细胞传感器CB10,并探究了其在不同检测条下的响应特征. 结果表明, 微生物全细胞传感器CB10在30 min内即可响应一定浓度的Cr6+; 其对Cr6+的检测最低限LOD为2 μmol·L-1; 当Cr6+的浓度为20~200 μmol·L-1时,CB10的响应能力与Cr6+浓度线性相关,进而传感器CB10可对该范围内的Cr6+生物可利用度进行定量分析(R2=0.98055); 当重金属诱导浓度为10~50 μmol·L-1时,CB10对Cr6+具有较强的响应特异性; 本研究也发现,较高浓度的Pb2+、Mn2+和Sb2+也可以产生对CB10的诱导能力; 诱导温度为30℃,pH为7时, CB10的响应效率最高; 诱导温度为15~30℃,pH为4~7时,CB10响应能力表现稳定. CB10具备较强的响应速率、灵敏度、特异性和稳定性,具备对水体重金属进行快速检测和土壤重金属的生物可利用进行评价的潜力. |
| 英文摘要 |
| A microbial whole-cell biosensor CB10 for the bioavailability assessing of Cr6+was constructed by molecular biotechnology. The regulatory gene and promoter of CB10 was from the chromium resistance system of plasmid pMOL28 from Cupriavidus metallidurans CH34, and the reporter gene of CB10 was luc which was derived from Photinus pyralis. Finally, its response characteristic was discussed under different incubation conditions e. g. pH and temperature. The results showed that a microbial whole-cell biosensor CB10 had been successfully constructed which could respond to Cr6+ within 30 min, with a LOD for Cr6+ of 2 μmol·L-1. When the incubation concentration of Cr6+ was between 20 μmol·L-1 and 200 μmol·L-1, the luc activity of the CB10 biosensor was in linear correlation with the concentration of Cr6+. When the concentration of heavy metal was in the range of 10-50 μmol·L-1, the response of CB10 was relatively more specific. Moreover, high concentrations of Pb2+, Mn2+and Sb2+ could also induce CB10.By analyzing the response characteristic of CB10 biosensor, we could draw the conclusion that 15-30℃ and pH 4-7 were appropriate for CB10, and 30℃ and pH 7 were the optimal conditions for the incubation of the CB10 biosensor. The microbial whole-cell biosensor CB10 for the detection of Cr6+ was fast-responding, specific, sensitive and stable under various conditions. In prospective, it could be used in the fast detection of Cr6+ in water and assessment of the bioavailability of Cr6+in soil. |
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