Collaborative Research: Phylogenetic and Physiological Characterization of Amino Acid Nitrogen Isotopes in Phytoplankton

合作研究：浮游植物氨基酸氮同位素的系统发育和生理学特征

• 批准号: 2242041
• 负责人: Lin Zhang
• 金额: $ 44.51万
• 依托单位: Texas A&M University Corpus Christi
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2242041&HistoricalAwards=false
• 关键词: Collaborative; Research; Phylogenetic; Physiological; Characterization

Phytoplankton are microscopic plants that live in the ocean and act as the base of the marine food web. These microorganisms use inorganic nitrogen (N) from the water to make a variety of amino acids. Some of the amino acids keep the initial chemical signature (i.e., N isotope value) of their N source. Other amino acids are involved in metabolic processes that change the initial chemical signature (N isotope value). These distinct N isotope signatures are passed along to organisms that consume phytoplankton and throughout the food web. Thus, the N isotope values of individual amino acids can be used to obtain the isotope value of N sources supporting food webs and to estimate the trophic position of organisms in biota, particles, coral skeletons, and sediments. But, this requires a clear understanding of the N isotope patterns of amino acids produced by phytoplankton. This project will examine whether different phytoplankton species produce amino acids with distinct N isotope patterns when using the same N source. The project will also study whether the N isotope patterns produced by the same species of phytoplankton change under different growth and environmental conditions. Information from this study will improve the ability to use N isotope values in amino acids in ecological and biogeochemical studies. This collaborative project combines novel research with broader impacts focused on engaging the public and promoting diversity and inclusion at various levels. Three graduate students and one postdoc will participate in the research. Research opportunities will be provided to undergraduate students, especially those with backgrounds. Students will be recruited through the McNair and Louis Stokes Alliances for Minority Participation program at Texas A&M Univ. at Corpus Christi, a Hispanic Serving and Minority Serving Institution. To share results broadly, the investigators and students will give talks about marine science to local K-12 students in Corpus Christi TX. The New Bedford High School (in MA) summer marine intern program will be engaged in this project. Public lectures will be given on the topic of algal blooms and a children’s article will be written on the topic of isotopes. Outcomes of this project will also be incorporated into presentations to the Chesapeake Bay Program, Maryland Harmful Algal Bloom Task Force, and the Scientific and Technical Advisory Committee of the Maryland Coastal Bays. The use of N isotope values of different amino acids (δ15N-AA) to retrieve the N source isotope signature of food webs and estimate trophic positions depends on information about the δ15N-AA produced by phytoplankton at the base of the food web which is still poorly understood. This study seeks to explore fundamental scientific questions to better understand δ15N-AA produced by phytoplankton. 1) Under the same nitrogenous nutrient and growth conditions, do δ15N-AA patterns vary between major phytoplankton groups? Are the unique δ15N-AA patterns in diatoms related to unique aspects of their N metabolism? 2) Do changes in phytoplankton physiology resulting from nitrogenous nutrient availability, N form utilized (ammonium, nitrate, and mixed), and/or other growth conditions independently produce significant changes in δ15N-AA? Phytoplankton samples will be collected from controlled culture (e.g., chemostat) experiments and from field studies in the Gulf of Mexico and Chesapeake Bay, especially during near-monospecific bloom events. By taking the advantage of newly developed analytical approaches, new knowledge of compound and intramolecular δ15N of poly-N AA such as arginine, asparagine, glutamine, and histidine in phytoplankton will be generated for the first time. This ground-truthing work will advance the understanding of δ15N-AA pattern produced by key phytoplankton species critical to the biological pump and harmful algal blooms under environmentally relevant physiological conditions. The expected outcomes from this work will enable new applications and more sophisticated trophic position analyses, studies of the efficiency of the ocean’s biological pump, and paleo-oceanographic reconstructions using amino acids preserved in natural archives.This project is funded by the Biological and Chemical Oceanography Programs.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.

浮游植物是生活在海洋中并充当海洋食品网的基础的微观植物。这些微生物使用水中使用无机氮（N）来制造各种氨基酸。一些氨基酸保留其N来源的初始化学特征（即N同位素值）。其他氨基酸参与了改变初始化学特征（N同位素值）的代谢过程。这些不同的同位素签名传递给消费浮游植物和整个食物网的组织。这是单个氨基酸的N同位素值可用于获得支持食物网的N源的同位素值，并估计组织在生物群，颗粒，珊瑚骨骼和沉积物中的营养位置。但是，这需要清楚地了解浮游植物产生的氨基酸的N同位素模式。该项目将检查使用相同的n个来源时，不同的浮游植物物种是否产生具有不同N同位素模式的氨基酸。该项目还将研究在不同的生长和环境条件下由相同种类的浮游植物变化产生的N同位素模式。这项研究的信息将提高生态和生物地球化学研究中氨基酸中使用N同位素值的能力。这个合作项目将新颖的研究与更广泛的影响相结合，重点是吸引公众并在各个层面上促进多样性和包容性。三名研究生和一名博士后将参加这项研究。研究机会将提供给本科生，尤其是那些背景的学生。将通过麦克奈尔（McNair）和路易斯·斯托克斯（Louis Stokes）联盟招募学生，以在德克萨斯州A＆M大学招募少数民族参与计划。在科珀斯克里斯蒂（Corpus Christi），西班牙裔和少数派服务机构。为了广泛分享结果，调查人员和学生将向Corpus Christi TX的本地K-12学生发表有关海洋科学的演讲。新的贝德福德高中（MA）夏季海洋实习计划将参与该项目。公开讲座将以藻类血液为主题，并将写有关同位素主题的儿童文章。该项目的成果也将被纳入切萨皮克湾计划，马里兰州有害藻类布鲁姆特遣队以及马里兰州沿海海湾的科学技术委员会的演讲中。不同氨基酸（Δ15N-AA）的N同位素值的使用来检索食物网的N源同位素特征和估计的营养位置取决于食物网基础上植物网植物网络中对Δ15N-AA的信息，这些信息仍然不足以理解。这项研究寻求1）在相同的氮营养和生长条件下，主要浮游植物组之间的Δ15N-AA模式会有所不同吗？硅藻中独特的Δ15N-AA模式是否与其N代谢的独特方面有关？ 2）氮的养分利用率，n形式（铵，硝酸盐和混合）和/或其他生长条件独立产生Δ15N-AA的显着变化？浮游植物样品将从受控培养（例如，化学仪）实验以及墨西哥湾和切萨皮克湾的现场研究中收集，尤其是在近乎单独的开花事件中。通过利用新开发的分析方法的优势，将首次生成浮游植物中多-N AA的化合物和分子内Δ15N，例如精氨酸，天冬氨氨酸，谷氨酰胺和组氨酸。这项接地工作将提高对在环境相关的生理条件下对生物泵和有害藻类血液至关重要的关键浮游植物物种产生的Δ15N-AA模式的理解。这项工作中的预期结果将实现新的应用和更复杂的营养位置分析，对海洋生物泵效率的研究以及使用氨基酸保留在自然档案中的氨基酸的古质量重建的研究。该项目由该项目提供了由Infortial Indernition te Indertional of Notial of Notial of Notial of deem the Inderial of deem the Inderial the Inderial of deem the Inderial the Inderial the Inderial the Inderial the Inderial the Inderial the Inder的资助影响审查标准。