Departamento de Microbiología-III, Facultad de Biología, C/. José Antonio Novais 2, Universidad Complutense, Madrid, Spain.
Microb Biotechnol. 2011 Jul;4(4):513-22. doi: 10.1111/j.1751-7915.2011.00252.x. Epub 2011 Mar 1.
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.
重金属是最严重的污染物之一，因此需要开发用于环境中重金属的灵敏和快速生物监测方法。生物利用度、毒性和遗传毒性等关键参数不能通过化学分析进行测试，而只能使用活细胞进行检测。全细胞生物传感器将整个细胞用作单个报告器，其中包含生物受体和换能器元件。在本文中，我们报告了使用两种基因构建体的结果，这两种基因构建体使用 Tetrahymena thermophila MTT1 和 MTT5 金属硫蛋白启动子与真核荧光素酶基因相连作为报告基因。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。创建了转化的 T. thermophila 菌株作为重金属全细胞生物传感器，并设计了生物测定法，以在大约 2 小时内检测受污染土壤或水样中的可利用重金属。使用人工和天然样本对这些全细胞生物传感器进行了验证，包括检测假阳性和假阴性的方法。与其他已发表的细胞生物传感器的比较表明，基于 Tetrahymena 金属硫蛋白启动子的生物传感器似乎是最敏感的真核金属生物传感器，与一些原核生物传感器相比也具有优势。
