SBIR Phase II: A Diffusion Gradient System for Studying Process and Behavior in Microbial and Cellular Biology

9502872 Koh本项目旨在进一步开发和测试一期研究中构建的扩散梯度系统。该系统由一个扩散梯度室（DGC）组成，用于培养微生物在多个连续的小可溶性分子扩散梯度中。此外，还有一个用于整合从DGCs流出的流出物的流出室，一个提供背光以可视化微生物生长的透光器，以及一个用于监测和量化微生物生长和运动的摄像系统。这一阶段的研究将侧重于改进和降低系统的成本，并展示其在研究微生物和细胞生物学中的各种问题方面的多功能性。研究了采用注射成型方法构建DGC的可行性。这将提高其质量并降低其成本。将设计和测试一个自动跟踪摄像机系统，以提高系统的定量能力。将测试一个包围整个系统并保持稳定温度的温度控制单元。该系统将与密歇根州立大学（MSU）合作，对其建立梯度的能力进行测试。将在DGC中测试许多溶质，并将经验结果与数学模型预测的结果进行比较。密歇根州立大学的科学家还将评估该系统在暴露于多种梯度的解毒细菌群落中跟踪种群变化的能力，他们将研究趋化性在确定的混合细菌培养物之间的竞争中的作用。此外，他们将使用DGC来阐明根瘤菌中使用报告基因响应环境刺激的基因表达模式。密歇根大学的一名科学家也将研究成骨细胞组织培养系对DGC施加梯度的生长和反应。

9502872 Koh This project is designed to further develop, and test the diffusion gradient system constructed during Phase I research. The system consists of a diffusion gradient chamber (DGC) for culturing microorganisms in multiple, continuous diffusion gradients of small soluble molecules. In addition, there is an effluent chamber for consolidating effluent flow from the DGCs, a transilluminator that provides back lighting to visualize microbial growth, and a camera system to monitor and quantify microbial growth and movement. This phase of the research will focus on refining and reducing the cost of the system, and demonstrating its versatility for studying a variety of problems in microbial and cellular biology. The feasibility of constructing the DGC by injection molding will be investigated. This would improve its quality and reduce its cost. An automated tracking camera system will be designed and tested that will enhance the quantitative power of the system. A temperature control unit that encloses the entire system and maintains a stable temperature will be tested. The system s capability to establish gradients will be tested in collaboration with Michigan State University (MSU). A number of solutes will be tested in the DGC and the empirical results will be compared with results predicted by a mathematical model Scientist at MSU will also evaluate the system s ability to track population changes in a detoxifying bacterial community exposed to multiple gradients, and they will study the role of chemotaxis in competition between defined mixed cultures of bacteria. In addition, they will use the DGC to elucidate patterns of gene expression in response to environmental stimulus using reporter genes in Rhizobium meliloti. A University of Michigan scientist will also study the growth and response of a tissue culture line of osteoblast cells to imposed gradients in the DGC.