Quantitative Studies of Bacterial Chemotaxis: Relationship to Cell Growth Optimization and Metabolic Preferences

自然栖息地中的细菌不断地改变环境 条件 为了最大限度地增长和生存，它们需要 来优化对这些不同条件的代谢反应。 他们的 主要的行为反应是改变自己的新陈代谢， 通过迁移改变它们的位置。 迁移是最快的方式， 对他们的回应。 趋化性，或细胞的偏向运动 在化学梯度的方向有利于他们的生存， 一种在各种能动细菌中普遍存在的现象。 对生物化学机制的基本科学理解 趋化性在过去的二十年中有了巨大的增长。 然而，趋化性对应用 生物技术的重要性在很大程度上被忽视了。 法律与正义党 提出了一套实验和理论相结合的研究， 为了解决与微生物种群行为相关的两个主要问题， 在生物和生物技术应用中。 （l.）如何趋化反应的营养引诱剂的变化， 细胞生长条件是多种多样的，这与 在非混合环境中优化细胞生长？ 2.）的情况。什么是网状细胞运动的反应， 相互冲突的趋化刺激，以及这如何取决于细胞 代谢偏好 实验工作将包括测量细菌运动性 使用PI自己设计的两种定量分析。 理论 工作将包括分析实验观察到的 对种群增长的趋化反应。获得的基本见解 这些调查可能对一些重要的 领域，如非混合系统中的微生物种群动力学，细胞 分离、生物传感器和细胞代谢状态监测。 PI被认为非常有资格执行 我建议这项研究将获得三项资助。 根据调整后的订正预算， 提议

Bacteria in natural habitats are continually changing environmental conditions. In order to maximize their growth and survival, they need to optimize the metabolic response to these varying conditions. Their primary behavioral responses are to modify their own metabolism and to change their location by migration. Migration is the quickest mode of response available to them. Chemotaxis, or the biased movement of cells in the direction of a chemical gradient favorable to their survival, is a phenomena found to be ubiquitous among a variety of motile bacteria. Basic scientific understanding of the biochemical mechanisms underlying chemotaxis has increased tremendously over the past two decades. However, the implications of chemotaxis for applications of biotechnological importance have largely been neglected. The PIs propose a set of combined experimental and theoretical studies intended to address two major questions relevant to microbial population behavior in biological and biotechnological applications. l.) How does the chemotactic response to nutrient attractants change as cell growth conditions are varied, and how is this related to optimization of cell growth in a non-mixed environment? 2.) What is the net cell movement response to multiple, perhaps conflicting, chemotactic stimuli, and how does this depend on cell metabolic preferences? The experimental work will include measurements of bacterial motility using two quantitative assays of the PIs' own design. The theoretical work will involve analysis of the effects of the experimentally observed chemotactic responses on population growth. Fundamental insights gained from these investigation may have implications on a number of important areas, such as microbial population dynamics in non-mixed systems, cell separations, biosensor and the monitoring of cell metabolic states. The PIs are considered to be extremely well qualified to carry out the proposed research and I recommend that this proposal be funded for three years in accordance with the adjusted revised budget submitted with this proposal.