Nitrogenase metal cofactors in terrestrial systems: Chemical speciation and the kinetic versus thermodynamic controls on metal acquisition by diazotrophs using metallophores

陆地系统中的固氮酶金属辅助因子：化学形态形成以及固氮生物利用金属载体获取金属的动力学与热力学控制

• 批准号: 0948259
• 负责人: Frank Black
• 金额: $ 17万
• 依托单位: Black Frank J
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948259&HistoricalAwards=false
• 关键词: Nitrogenase; metal; cofactors; terrestrial; systems

Dr. Frank J. Black has been granted the NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at Princeton University. The research will contribute to the understanding of how the amount and forms of trace metals (Mo and V) in soils and leaf litter influence the activity of free living nitrogen fixing bacteria, and how these bacteria tailor their strategies for metal acquisition to adapt to different soil environments. The research to be conducted aims to understand (1) what forms of vanadium and molybdenum are found in soils and leaf litter where nitrogen fixation occurs, (2) how available these different forms are to nitrogen fixing bacteria, and (3) which mechanisms developed by bacteria to acquire these metals are more effective under different soil conditions. Bacteria have developed various approaches to acquiring iron in soils even from normally unavailable forms, and this research will test how effective bacteria are at acquiring molybdenum and vanadium under similar conditions. Plant growth and CO2 utilization in many ecosystems is limited by the availability of the nutrient nitrogen. Some soil bacteria are able to fix nitrogen from the atmosphere and make it bioavailable, but in order to do so they require a combination of the metals molybdenum, vanadium, and iron. These metals are often in short supply in soils (e.g., molybdenum), or are bound in forms not readily accessible to bacteria (e.g., iron). The low availability of these metals in soil environments is a potentially important control on nitrogen fixation, and in turn on the productivity of entire ecosystems. Teaching and educational outreach activities associated with the project will include helping to design and teach the laboratory section of a freshman seminar course using inquiry based techniques.

弗兰克·布莱克（Frank J. Black）博士被授予NSF地球科学博士后奖学金，以在普林斯顿大学执行研究和教育计划。这项研究将有助于理解土壤和叶子中微量金属（MO和V）的数量和形式如何影响自由生存氮固定细菌的活性，以及​​这些细菌如何量身定制其金属采集策略以适应不同的土壤环境。 要进行的研究旨在了解（1）在发生氮固定的土壤和叶窝中发现了哪种形式的钒和钼，（2）在不同的土壤条件下获得这些不同的这些不同形式的氮固定细菌以及（3）哪些机制在不同的土壤中获得这些机制。 细菌甚至从通常无法获得的形式中开发了各种方法来在土壤中获取铁，这项研究将测试在类似条件下获得钼和钒的有效细菌的有效性。 许多生态系统中的植物生长和二氧化碳利用受到养分氮的可用性的限制。 一些土壤细菌能够从大气中固定氮并使其具有生物利用度，但是为了这样做，它们需要将金属钼，钒和铁的混合物组合在一起。 这些金属通常在土壤（例如钼）中供不应求，或者以细菌不易接近的形式结合（例如铁）。 这些金属在土壤环境中的可用性低是对氮固定的潜在重要控制，进而对整个生态系统的生产力进行了控制。与该项目相关的教学和教育外展活动将包括使用基于询问的技术帮助设计和教授新生研讨会课程的实验室部分。