Impedance Cytometry for Rapid Biosensing of Lipid Content in Algal Cultures

PI名称：Brian Kirby Proposal编号：1605574显微藻类是生物燃料可持续生产的一个有前途的未来平台。这些生物利用阳光、大气中的二氧化碳以及溶解在液体介质中的氮和磷等营养物质来制造脂类，这些脂类可以加工成液体运输燃料。露天池塘中藻类的生长，以及藻类对脂肪的积累，在一天或一周内可能会有很大的差异。这就需要经常监测藻类的生产力，以便制定生产计划。然而，目前测量藻类生产力既耗时又昂贵，需要人工采样和复杂的分析仪器。该项目的目标是开发一种简单、实时的传感器，用于在不断变化的养殖环境中监测藻类脂肪。这项拟议的工作将开发一种传感器平台，当单个藻细胞流经显微镜毛细管时，该平台可以测量它们的电学特性。电学性质的变化与藻细胞中储存的脂类的数量和类型有关。与该项目相关的教育活动包括一个由学生举办的技术会议，旨在为康奈尔大学机械工程研究生项目的学生提供多样化的指导。在用于生产藻类生物燃料的室外池塘养殖系统中，藻细胞的生长和脂肪积累对不断变化的液体营养介质组成、温度和日照强度非常敏感。在这些变化的条件下，包含两种或两种以上具有不同新陈代谢和生色团的藻类的共培养可能会增加整个培养平台的稳定性。然而，藻类细胞中的脂肪产生通常是由营养饥饿引发的，这增加了系统的时间复杂性。有必要通过简单的测量来监测和总结所有这些生物复杂性，这些测量描述了共培养的总体脂肪生产力以及单个亚群的脂肪生产力。这项拟议的研究将开发一种微流控介电阻抗监测器，用于快速检测单个藻细胞中的脂类，并表征藻类共培养中的脂类储存，以阐明混合菌株培养的效果。该项目有三个目标。第一个目标是表征饥饿诱导的普通小球藻、莱茵衣藻和新绿藻的介电性质变化，并将这些变化与生物量密度和脂类和淀粉的封存联系起来。第二个目标是验证流动阻抗细胞术测量脂肪和淀粉积累的核磁共振(核磁共振)和高效液相色谱。第三个目标是通过单细胞和大量脂类特征来表征藻类多样性在混合物种养殖中的作用。

PI Name: Brian KirbyProposal Number: 1605574Microscopic algae are a promising future platform for the sustainable production of biofuels. These organisms use sunlight, atmospheric carbon dioxide, and nutrients such as nitrogen and phosphorous dissolved in liquid medium to make lipids which can be processed into liquid transportation fuel. The growth of algae in outdoor open ponds, and the accumulation of lipids by the algae, can vary considerably during the day or week. This requires frequent monitoring of algal productivity for production planning. However, measurement of algal productivity is presently time consuming and costly, requiring manual sampling and sophisticated analytical instruments. The goal of this project is to develop a simple, real-time sensor for monitoring algal lipids in a cultivation environment that is constantly changing. The proposed work will develop a sensor platform that measures the electrical properties of single algal cells as they flow through a microscope capillary tube. The change in electrical properties is correlated to the amounts and types of lipid stored within the algal cell. The educational activities associated with the project feature a student-run technical conference designed to diversify and provide mentorship for students in the Mechanical Engineering graduate program at Cornell University. In outdoor pond cultivation systems used for algal biofuel production, the growth and lipid accumulation in algal cells are sensitive to constantly changing liquid nutrient medium composition, temperature, and sunlight intensity. Co-cultures containing two or more species of algae that have disparate metabolisms and chromophores may add stability to the overall cultivation platform under these changing conditions. However, lipid production in algal cells is often triggered by nutrient starvation, which adds to the temporal complexity of the system. There is a need to monitor and summarize all of this biological complexity with simple measurements that describe the overall lipid productivity of the co-culture as well as lipid productivity of individual sub populations. The proposed research will develop a microfluidic dielectric impedance monitor for rapid lipid detection in single algal cells and characterize lipid storage in algal co-cultures to elucidate mixed-strain culture effects. The project has three objectives. The first objective is to characterize starvation-induced, dielectric-property shifts in Chlorella vulgaris, Chlamydomonas reinhardtii, and Neochloris oleoabundans and relate these shifts to biomass density and sequestration of lipids and starches. The second objective is to validate the flow-impedance cytometry measurements of lipid and starch accumulation by nuclear magnetic resonance (NMR) and high-performance liquid chromatography. The third objective is to characterize the role of algal diversity with single-cell and bulk characterization of lipids in mixed-species culture.