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Collaborative Research: Establishing the Hydrogen Isotopic Window into Archaeal Lipid Biomarkers

合作研究：建立古细菌脂质生物标志物的氢同位素窗口

基本信息

批准号：
1928309
负责人：
William Leavitt
金额：
$ 27.49万
依托单位：
Dartmouth College
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2023-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1928309&HistoricalAwards=false
关键词：
Collaborative Research Establishing Hydrogen Isotopic

项目摘要

Life has three major groups - the eukaryotes, bacteria and archaea. This work focuses on the often-overlooked archaea. They are microbes critical to the cycling of matter and energy on Earth. They have played this important role throughout the history of the planet. Like all life on Earth, archaea are made up of elements such as carbon, oxygen and hydrogen. These elements form larger organic molecules that are required by all life such as DNA, proteins, and lipids. Geobiologists study these organic molecules to learn about life on Earth today and in the past. However, not all of these are preserved over long periods of time. Most DNA and proteins break down quickly and can only be used to study Earth today. Lipids are often much hardier and so are useful to geobiologists because they can be preserved in rocks for millennia. Lipids from archaea are particularly hardy and do not break down easily. This means that they can store information about the place in which the microbe lived. Long after they die, the lipids made by archaea can be extracted from muds, oils, and rocks. Geobiologists examine the structures and atoms of these lipids built by archaea millions of years ago to learn about Earth's past. However, it is not easy to decode the information in the lipids of long dead microbes correctly. To do this well, it is important to study these same lipids in modern systems and in the lab. This project will study several important archaea in the lab and shed light on how the different kinds of hydrogen atoms are used by archaea to build their lipids. The results will lead to advances in interpreting what lipids from archaea can tell us about the places they lived recently, and millions of years in the past. The proposed project emphasizes training of students at all levels and this includes advanced graduate (PhD and MS trainees) as well as undergraduate, high-school and middle school students. To engage high-school and middle school students in underserved districts, project members will use a graduate and undergraduate led peer-to-peer mentoring network called ManyMentors. This is an app-based mentoring platform that matches students in underserved classrooms who show interest in STEM with undergraduate and graduate students seeking STEM degrees. Specific teaching activities are all aimed at fostering transferrable skills. This includes critical thinking, written and verbal communication, and coding-literacy. All project members will participate in these activities. Archaea are a domain of life central to the cycling of matter and energy in low temperature (150 Celsius) environments today and throughout Earth's history. The primary objective of this project is to uncover how the hydrogen (H) isotopic composition of archaeal lipid biomarkers records geochemical and geomicrobial processes and may be used to reconstruct modern environmental systems and the recent geologic past. To read these records requires controlled experimental calibration of archaeal biomarker H isotope fractionation, which does not yet exist. This work will address this knowledge gap by calibrating the lipid H-isotopic signature of representative archaea across different redox regimes, carbon sources and energy fluxes reflecting the full suite of environments encountered in nature. Specifically, it will test the hypothesis that the structural and H-isotopic composition of archaeal lipids records the main hypothesized geochemical drivers of variability in archaeal biomarkers (energy and carbon availability, as well as nutrient/energy flux). To achieve this, the proposed work will employ a mixture of culturing methods including rate-controlled steady-state (chemostatic) experiments, combined with archaeal lipid characterization, compound-specific H isotope analysis, and a modeling effort. The output of this work will be a process- and mechanism-based interpretive framework for archaeal lipid H isotope fractionation in response to environmental forcings. That is, the proposed work will allow for (re)interpretations of past and present biogeochemical processes across wide temporal and spatial scales, from planetary (exosphere redox) to regional (basinal redox) to interfacial (pore-water redox). This project will train two PhD students in low temperature geochemistry and geomicrobiology and provide myriad opportunities to engage undergraduate students from diverse backgrounds in basic scientific research. Student engagement will be guided by an emphasis on critical thinking, lab and analytical skills building, and exposure to new ideas and questions in geomicrobiology. This will allow student to gain transferrable skills, such as rational experimental design, hypothesis construction and testing, and coding-literacy in the geosciences. These are requisite skills in the 21st century workforce, both in and out of the geosciences. Co-PI Kopf has a demonstrated commitment to open-source code, data collection and analysis software and has deployed such modules in the classroom as part of a larger effort to increase coding-literacy in geoscience courses. To expand the impact of coding modules developed at CU Boulder, Co-PI Leavitt will test and implement them in geomicrobiology and biogeochemistry courses at Dartmouth. Both PIs are committed to experimental pre-registration (via Open Science Framework) and the long-term archiving and preservation of all data products. All PIs and team members will participate in the ManyMentors network.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.

生命有三大类--真核生物、细菌和古生菌。这项工作的重点是经常被忽视的古菌。它们是对地球上物质和能量循环至关重要的微生物。它们在地球的整个历史中发挥了重要作用。像地球上的所有生命一样，古生菌由碳、氧和氢等元素组成。这些元素形成了所有生命所需的更大的有机分子，如DNA，蛋白质和脂质。地球生物学家研究这些有机分子，以了解地球上的生命在今天和过去。然而，并非所有这些都能长期保存。大多数DNA和蛋白质很快就会分解，只能用于研究今天的地球。脂质通常更坚固，因此对地质生物学家很有用，因为它们可以在岩石中保存数千年。古生菌中的脂质特别哈代，不易分解。这意味着它们可以存储有关微生物生活的地方的信息。在古细菌死亡很久之后，它们所制造的脂质可以从泥土、石油和岩石中提取出来。地球生物学家研究了数百万年前古生菌构建的这些脂质的结构和原子，以了解地球的过去。然而，要正确解码长期死亡的微生物脂质中的信息并不容易。为了做好这一点，重要的是在现代系统和实验室中研究这些相同的脂质。该项目将在实验室中研究几种重要的古细菌，并阐明古细菌如何使用不同种类的氢原子来构建脂质。这些结果将有助于解释古生菌的脂质可以告诉我们他们最近生活的地方，以及过去数百万年的地方。拟议的项目强调对各级学生的培训，其中包括高级研究生（博士和硕士学员）以及本科生、高中生和中学生。为了吸引服务水平低下地区的高中生和中学生，项目成员将使用一个名为ManyMentors的研究生和本科生领导的点对点指导网络。这是一个基于应用程序的指导平台，将那些对STEM感兴趣的学生与寻求STEM学位的本科生和研究生相匹配。具体的教学活动都是为了培养可迁移的技能。这包括批判性思维，书面和口头沟通，以及编码素养。所有项目成员都将参加这些活动。深海是生命的一个领域，对今天和整个地球历史上低温（150摄氏度）环境中的物质和能量循环至关重要。该项目的主要目标是揭示古生物脂质生物标志物的氢（H）同位素组成如何记录地球化学和地质微生物过程，并可用于重建现代环境系统和最近的地质历史。要读取这些记录，需要对古生菌生物标志物H同位素分馏进行受控实验校准，而这种校准尚不存在。这项工作将通过校准代表性古细菌在不同氧化还原体系，碳源和能量通量中的脂质H-同位素特征来解决这一知识缺口，这些特征反映了自然界中遇到的全套环境。具体来说，它将测试的假设，古生菌脂质的结构和氢同位素组成记录的主要假设的古生菌生物标志物（能源和碳的可用性，以及营养/能量通量）的变化的地球化学驱动因素。为了实现这一目标，拟议的工作将采用混合培养方法，包括速率控制稳态（恒化）实验，结合古菌脂质表征，化合物特异性H同位素分析和建模工作。这项工作的输出将是一个过程和机制为基础的解释框架古菌脂质H同位素分馏环境强迫。也就是说，拟议的工作将允许（重新）解释过去和现在的地球化学过程跨越广泛的时间和空间尺度，从行星（外逸层氧化还原）区域（盆地氧化还原）界面（孔隙水氧化还原）。该项目将培养两名低温地球化学和地质微生物学博士生，并提供无数机会让不同背景的本科生参与基础科研。学生的参与将通过强调批判性思维，实验室和分析技能建设，以及接触新的想法和问题在地质微生物学的指导。这将使学生获得可转移的技能，如合理的实验设计，假设的构建和测试，以及在地球科学的编码素养。这些都是21世纪世纪劳动力的必备技能，无论是在地球科学领域还是在地球科学领域。Co-PI Kopf对开源代码、数据收集和分析软件有着明确的承诺，并在课堂上部署了这些模块，作为提高地球科学课程编码素养的更大努力的一部分。为了扩大在CU博尔德开发的编码模块的影响，合作PI莱维特将在达特茅斯的地球微生物学和地球化学课程中测试和实施它们。这两个PI都致力于实验性预注册（通过开放科学框架）以及所有数据产品的长期存档和保存。该奖项反映了NSF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。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Controls on the hydrogen isotope composition of tetraether lipids in an autotrophic ammonia-oxidizing marine archaeon

DOI：
10.1016/j.gca.2023.04.033
发表时间：
2023-05
期刊：
Geochimica et Cosmochimica Acta
影响因子：
5
作者：
W. Leavitt;S. Kopf;Y. Weber;B. Chiu;J. McFarlin;F. Elling;S. Hoeft-McCann;A. Pearson
通讯作者：
W. Leavitt;S. Kopf;Y. Weber;B. Chiu;J. McFarlin;F. Elling;S. Hoeft-McCann;A. Pearson

Determination of the δ 2 H values of high molecular weight lipids by high temperature GC coupled to isotope ratio mass spectrometry

高温 GC 联用同位素比质谱法测定高分子量脂质的 δ 2 H 值

DOI：
10.1002/rcm.8983
发表时间：
2020
期刊：
Rapid Communications in Mass Spectrometry
影响因子：
2
作者：
Lengger, Sabine K.;Weber, Yuki;Taylor, Kyle W.R.;Kopf, Sebastian H.;Berstan, Robert;Bull, Ian D.;Mayser, Jan‐Peter;Leavitt, William D.;Blewett, Jerome;Pearson, Ann
通讯作者：
Pearson, Ann

Distribution and abundance of tetraether lipid cyclization genes in terrestrial hot springs reflect pH