Collaborative Research: Characterization of Iron Binding Organic Ligands in Seawater

合作研究：海水中铁结合有机配体的表征

• 批准号: 0751733
• 负责人: Daniel Repeta
• 金额: $ 46.8万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0751733&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterization; Iron; Binding

OCE-0751733OCE-0751822Iron is an essential element in many key biochemical processes, including respiration, nitrogen fixation, nitrate reduction, and chlorophyll biosynthesis. Iron speciation measurements show that 99% of dissolved iron is complexed by organic ligands that form very strong ferri-organic complexes that help stabilize Fe(III) in seawater, increasing its concentration to levels that can sustain microbial growth. However, the composition of these ligands that play an important role in the marine iron cycle remains largely unknown. Scientists from Woods Hole Oceanographic Institution and the University of Southern California propose to characterize the naturally occurring iron-binding ligands. Specifically, the investigators plan to collect strong iron-binding ligands from very large volume (104 L) samples and perform detailed spectral analysis (mass spectrometry and nuclear magnetic resonance spectroscopy) to determine ligand distributions, functional group characteristics, and ultimately the structures of major ligands. Preliminary results from the North Pacific Ocean show our collection protocol recovers 60% of Fe-ligand complexes and 25-30% of total ligands. Measured conditional stability constants of the ligand extract (Kcond L/Fe' 1012) and competitive isotopic (55Fe and Ga (III)) labeling in the presence of strong chelators (EDTA, DTPA, DFB) allows us to target only strong ligands for spectral analysis. Characterization of naturally occurring iron binding ligands would provide a better understanding of iron speciation in seawater, and complement on-going studies of Fe-ligand bioavailability in pure cultures and mixed assemblages of marine plankton.As regards broader impacts, a Fulbright postdoctoral scholar would participate in the research. One graduate student from the University of Southern California would be supported and trained as part of this project. One high school student would also be supported and trained as part of this project at the Woods Hole Oceanographic Institution. In addition, it is anticipated that undergraduate students supported via the Woods Hole Oceanographic Institution summer student fellowship program would participate in the study.

OCE-0751733OCE-0751822RIOR是许多关键生化过程中的重要元素，包括呼吸，氮固定，硝酸盐还原和叶绿素生物合成。 铁物种形成测量表明，有机配体有99％的溶解铁，这些配体形成非常强大的铁线有机络合物，有助于稳定海水中的Fe（III），将其浓度提高到可以维持微生物生长的水平。 但是，这些配体在海洋铁循环中起重要作用的组成仍然很大程度上未知。 来自伍兹孔海洋学机构和南加州大学的科学家提出了自然存在的铁结合配体的特征。 具体而言，研究人员计划从非常大容量（104 L）样品（104 L）样品中收集强的铁结合配体，并进行详细的光谱分析（质谱和核磁共振光谱），以确定配体分布，功能组特征，并最终降低主要配体的结构。 北太平洋的初步结果表明，我们的收集方案恢复了60％的Fe-配体配合物和总配体的25-30％。 在存在强螯合剂（EDTA，DTPA，DFB）的情况下，配体提取物（KCOND L/Fe'1012）和竞争同位素（55FE和GA（III））标记的有条件稳定性常数和竞争同位素（55FE和GA（III））标记。自然存在的铁结合配体的表征将更好地理解海水中的铁物种形成，并补充了对纯培养物中的Fe-crigand生物利用度的持续研究和海洋浮游生物的混合组合。正如更广泛的影响时，富布赖特的后遗传学学者将参与研究。 作为该项目的一部分，将为南加州大学的一名研究生提供支持和培训。 在伍兹霍尔海洋学院（Woods Hole Oceanographic Institution）的该项目的一部分，还将为一名高中生提供支持和培训。 此外，预计通过伍兹孔海洋学机构夏季学生奖学金计划获得支持的本科生将参加这项研究。