Synthetic biology-based detection of micronutrients with minimal equipment

项目摘要 这项拟议工作的目标是创造能够检测微量营养素(维生素)水平的细菌 或矿物)，最终应用于人体血液测试。未来的微量营养素 检测到的是锌。这些单元将使以后开发最小设备测试成为可能 偏远、资源贫乏地区的血液锌水平，在这两个时间段都有显著改善 以及使用当前最先进的方法所需的成本。这些细胞使用一种遗传电路 受锌敏感转录因子控制产生不同颜色的色素 样品中的锌浓度，表明锌含量是可接受的还是低的。因此， 这些细胞的功能就像是一种简单易懂的“细菌石蕊测试”。强有力的前期工作支持 我们成功的可能性。第一个目标是创造能够 产生三种不同的色素，以响应不同水平的细胞外锌。第二 目的包括使现有的电路抑制色素的产生直到进行检测， 允许对无色细胞进行预培养，从而实现快速着色和克服 人类血液样本中感受器细胞存活的障碍。第三个目标包括调整 细胞在实际血液样本中培养时的性能，因为到目前为止的工作都是使用实验室 生长介质可能产生与长期目标样品中的生长不同的结果。 该项目将产生可用于有史以来第一次细菌血液的基础技术 对低资源环境进行测试，以提供对微量营养素状况的人口水平评估。通过 由于成本低，基本上是医疗点，这样的长期结果将使营养 流行病学家和政策制定者在营养方面做出更明智的决定 干预措施，以及事后评估干预措施的成功情况，可能会有所改善 数百万营养不良者的健康。此外，产生色素的遗传电路 建立了一个可应用于其他微量营养素传感器开发的框架 使用不同的营养结合蛋白，潜在地允许进行一系列廉价的测试。

Project Summary The goal of the proposed work is to create bacteria that detect the level of a micronutrient (vitamin or mineral) in a sample, with ultimate application to human blood tests. The micronutrient to be detected is zinc. These cells will enable the later development of minimal-equipment testing of blood zinc levels in remote, resource-poor locations, a significant improvement in both the time and cost necessary using current state-of-the-art methods. The cells use a genetic circuit controlled by zinc-sensitive transcription factors to produce different colored pigment based on the zinc concentration in the sample, indicating whether zinc levels are acceptable or low. Thus, the cells function as a sort of easy-to-read “bacterial litmus test”. Strong preliminary work supports the likelihood of our success. The first aim involves creating the bacterial strain capable of producing three different pigments in response to different levels of extracellular zinc. The second aim involves making the existing circuit repress pigment production until the assay is performed, allowing for the pre-culture of colorless cells that will enable fast coloration and overcome obstacles to sensor cell survival in human blood samples.The third aim consists of tuning the cells' performance when grown in actual blood samples, since work to date has used laboratory growth medium which may yield different results than growth in the long-term target samples. This project will yield the underlying technology that can be used for the first-ever bacterial blood test for low-resource settings to provide population-level assessment of micronutrient status. By being low-cost and essentially point-of-care, such a long-term result would enable nutritional epidemiologists and policymakers to make more informed decisions about nutritional interventions, as well as to assess the success of interventions after the fact, potentially improving the health of millions of undernourished people. Moreover, the pigment-producing genetic circuit establishes a framework that can be applied for the development of other micronutrient sensors using different nutrient-binding proteins, potentially allowing a whole panel of inexpensive tests.