Whole-cell biosensors for detection of heavy metal ions in environmental samples based on metallothionein promoters from Tetrahymena thermophila
Whole-cell biosensors for detection of heavy metal ions in environmental samples based on metallothionein promoters from Tetrahymena thermophila
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DOI：
10.1111/j.1751-7915.2011.00252.x
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发表时间：
2011-07-01
影响因子：
5.7
通讯作者：
Gutierrez, Juan-Carlos
中科院分区：
文献类型：
--
作者：
Amaro, Francisco;Turkewitz, Aaron P.;Gutierrez, Juan-Carlos
重金属是最严重的污染物之一，因此需要开发灵敏、快速的环境中重金属生物监测方法。生物利用度、毒性和遗传毒性等关键参数无法使用化学分析进行测试，而只能使用活细胞进行测定。全细胞生物传感器使用全细胞作为包含生物受体和换能器元件的单个报告器。在本文中，我们报告了使用与真核荧光素酶基因连接的嗜热四膜虫 MTT1 和 MTT5 金属硫蛋白启动子作为报告基因的两个基因构建体的结果。这是首次报道纤毛原生动物用作重金属全细胞生物传感器。 T.thermophila 转化菌株被创建为重金属全细胞生物传感器，并设计启动生物测定法，在约 2 小时内检测污染土壤或水生样品中的生物可利用重金属。使用人造和天然样品对这些全细胞生物传感器进行了验证，包括检测假阳性和阴性的方法。与其他已发表的细胞生物传感器的比较表明，基于四膜虫金属硫蛋白启动子的生物传感器似乎是最灵敏的真核金属生物传感器，并且与一些原核生物传感器相比也毫不逊色。
Heavy metals are among the most serious pollutants, and thus there is a need to develop sensitive and rapid biomonitoring methods for heavy metals in the environment. Critical parameters such as bioavailability, toxicity and genotoxicity cannot be tested using chemical analysis, but only can be assayed using living cells. A whole-cell biosensor uses the whole cell as a single reporter incorporating both bioreceptor and transducer elements. In the present paper, we report results with two gene constructs using the Tetrahymena thermophila MTT1 and MTT5 metallothionein promoters linked with the eukaryotic luciferase gene as a reporter. This is the first report of a ciliated protozoan used as a heavy metal whole-cell biosensor. T. thermophila transformed strains were created as heavy metal whole-cell biosensors, and turn on bioassays were designed to detect, in about 2 h, the bioavailable heavy metals in polluted soil or aquatic samples. Validation of these whole-cell biosensors was carried out using both artificial and natural samples, including methods for detecting false positives and negatives. Comparison with other published cell biosensors indicates that the Tetrahymena metallothionein promoter-based biosensors appear to be the most sensitive eukaryotic metal biosensors and compare favourably with some prokaryotic biosensors as well.