Cr^(6+)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  

Construction and Properties of a Microbial Whole-cell Sensor CB10 for the Bioavailability Detection of Cr^(6+)

作　　者：侯启会[1] 马安周[1] 庄绪亮[1] 庄国强[1] 

机构地区：[1]中国科学院生态环境研究中心中科院环境生物技术重点实验室,北京100085

出　　处：《环境科学》2013年第3期1181-1189,共9页Environmental Science

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-YW-JS401;KSCX2-YW-G-072);国家高技术研究发展计划(863)项目(2007AA06A407);国家科技支撑计划项目(2012BAJ24B01)

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2μmol·L-1;当Cr6+的浓度为20～200μmol·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=0.980 55);当重金属诱导浓度为10～50μmol·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.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 CBIO 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-l, 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 CBIO was relatively more specific. Moreover, high concentrations of Pb2＋ , Mn2＋ and Sb2＋ could also induce CB10. By analyzing the response characteristic of C B10 biosensor, we could draw the conclusion that 15-30＋C and pH 4-7 were appropriate for C B10, and 30＋C 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.

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 

分 类 号：X172[环境科学与工程—环境科学]