Impedance Cytometry for Rapid Biosensing of Lipid Content in Algal Cultures

PI姓名：Brian Kirby提案编号：1605574微观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质，这些脂质可以加工成液体运输燃料。 室外开放池塘中藻类的生长以及藻类的脂质积累在一天或一周内可能会有很大变化。 这就需要经常监测藻类生产力，以便制定生产计划。 然而，目前藻类生产力的测量是耗时和昂贵的，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的实时传感器，用于在不断变化的培养环境中监测藻类脂质。 拟议的工作将开发一个传感器平台，测量单个藻类细胞流过显微镜毛细管时的电特性。 电特性的变化与藻类细胞内储存的脂质的数量和类型相关。 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课程的学生提供多样化和指导。 在用于藻类生物燃料生产的室外池塘培养系统中，藻类细胞中的生长和脂质积累对不断变化的液体营养培养基组成、温度和阳光强度敏感。 含有两种或更多种具有不同代谢和发色团的藻类的共培养物可以在这些变化的条件下增加整个培养平台的稳定性。 然而，藻类细胞中脂质的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。 需要用描述共培养物的总体脂质生产率以及单个亚群的脂质生产率的简单测量来监测和总结所有这种生物学复杂性。 拟议的研究将开发一种微流体介电阻抗监测器，用于快速检测单个藻类细胞中的脂质，并表征藻类共培养物中的脂质储存，以阐明混合菌株培养效应。 该项目有三个目标。 第一个目标是表征饥饿引起的，介电性质的变化，小球藻，莱茵衣藻，和Neochloris oleoabundans和这些变化与生物质密度和封存的脂质和淀粉。第二个目的是验证通过核磁共振（NMR）和高效液相色谱法的脂质和淀粉积累的流式阻抗细胞术测量。 第三个目标是表征藻类多样性的作用与单细胞和散装表征的脂质混合种文化。

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.