Environmental Lipidomics of Suspended and Sinking Particles in the Upper Ocean

海洋中的浮游生物在调节地球方面起着重要作用。这是由于它们在二氧化碳循环中的作用。例如，一些浮游生物利用光合作用将二氧化碳转化为组成细胞的有机分子。这些有机分子中约有四分之一是脂质，它们作为膜的结构成分、油体的能量储备和信号分子发挥着重要作用。在一些浮游细胞中，有一千多种不同类型的脂质分子，每一种都在细胞的新陈代谢中起着独特而重要的作用。浮游脂质对人类也很重要。地球科学家测量它们是为了解决各种各样的问题，从了解地球上的生命是什么时候进化的，到估计过去地质时期海洋的温度，再到评估浮游生物的健康状况及其进行光合作用的能力。浮游脂质也是石油的主要成分，石油是运输和工业的重要能源。最后，海洋浮游生物是许多“必需”脂类的唯一来源，这些脂类是人类从饮食中需要的，但不能有效地自我合成。值得注意的例子是二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），它们在人类心血管健康、激素产生和炎症管理中起着关键作用。平均而言，全球人口长期缺乏EPA和DHA。海鲜基本上是人类饮食中这些必需脂肪酸的唯一来源，然而我们不知道海洋生物生产这些脂质是否能够跟上未来全球的需求。尽管浮游生物的脂质很重要，但地球科学家对海洋中的脂质分布只有基本的了解，无法预测未来全球变暖下脂质将如何变化。浮游植物培养的实验室实验结果表明，未来海洋中产生的脂类的类型和数量可能会发生重大变化。作为该项目的一部分，正在进行的研究试图通过对海洋中的脂质进行首次全球规模的评估来解决这一问题。总体策略将是应用脂质组学，这是一种同时分析浮游生物细胞中所有脂质的最先进的方法，用于从广泛的海洋环境中获得数千个样本的文库。在影响浮游生物脂质代谢的因素中，这些环境几乎跨越了全球范围。该项目将揭示浮游生物脂质巨大多样性的身份、来源和命运，并使科学家能够预测和应对未来海洋脂质输出的变化。该项目还将使我们了解石油的形成，并为地球科学家提供更好的工具来了解地球的历史。这位科学家将继续努力培养下一代科学家（博士后），并通过他的科学推广努力教育社区和K-12学生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Plankton in the ocean play an important role in regulating Earth?s climate due to their role in cycling carbon dioxide. For example, some plankton use photosynthesis to convert carbon dioxide into the organic molecules that compose their cells. About a quarter of these organic molecules are lipids, which serve important roles as structural components of membranes, as energy reserves in oil bodies, and as signaling molecules. In some planktonic cells there are over one thousand different types of lipid molecules, each playing a distinct and essential role in the metabolism of the cell. Planktonic lipids are also important for humans. They are measured by geoscientists in order to address a wide variety of problems, from understanding when life evolved on Earth, to estimating the temperature of the ocean in geological past, to assessing the health of plankton and their ability to conduct photosynthesis. Planktonic lipids are also the main components of petroleum, a critical energy source for transportation and industry. Finally, ocean plankton are the sole sources of many "essential" lipids that humans require in their diet but cannot efficiently synthesize themselves. Notable examples are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which in humans play key roles in cardiovascular health, hormone production, and inflammation management. On average, the global population of humans is chronically deficient in EPA and DHA. Seafood is essentially the only source of these essential fatty acids to the human diet, and yet we do not know if production of these lipids by marine organisms will be able to keep up with future global demand.Despite the importance of planktonic lipids, geoscientists have only a basic understanding of lipid distributions in the ocean and cannot predict how lipids will change in response to future global warming. Results from lab experiments with cultures of phytoplankton suggest the potential for significant future alterations in the types and amounts of lipids produced in the oceans. The research being conducted as part of this project seeks to address this problem by producing the first global-scale assessment of lipids in the ocean. The overarching strategy will be to apply lipidomics, a state-of-the-art method for simultaneously analyzing all of the lipids in a plankton cell, to a library of thousands of samples from a broad range of ocean environments. These environments nearly span the global range in factors thought to affect plankton lipid metabolism. This project will shed new light on the identity, sources, and fates of the vast diversity of planktonic lipids, and enable scientists to predict and respond to changes in the future output of lipids from the ocean. The project will also inform our understanding of petroleum formation, and provide geoscientist with better tools for understanding Earth's history. The scientist would continue his efforts to train the next generation of scientists (postdoc), as well as his quest to educate the community and K-12 students via his science outreach endeavors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.