Collaborative Research: Physiology, Ecology, and Biochemistry of Nitrogen Fixation by Marine Planktonic Microorganisms (ABR)

合作研究：海洋浮游微生物固氮的生理学、生态学和生物化学（ABR）

• 批准号: 9317738
• 负责人: Gordon Taylor
• 金额: $ 23.95万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-01 至 1996-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9317738&HistoricalAwards=false
• 关键词: Collaborative; Research; Physiology; Ecology; Biochemistry

Carpenter 9317738 This project continues studies into the ecology, physiology and biochemistry of Trichodesmium and other planktonic N2 fixers, undertaking several cruises in more widespread areas of tropical North Atlantic, W Caribbean, NE & NW Australia than pervious efforts. One objective is to assess Trichodesmium population abundance and N2 fixation along with concurrent assessment of phytoplankton population abundance and N assimilation, new and regenerated nitrogen. Species distinctions will be done using ultrastructure and nifH gene sequencing. This will involve protein labeling and ultrastructural studies and molecular biological approaches. The next objective is to determine whether the phenomenon of diel periodicity in nitrogenase activity is a common characteristic of these populations as well as further examining the basis for this periodicity and the mechanisms of O2 protection. The project will continue to examine the fate of Trichodesmium C and N, determine the release rates of labile organics (glutamate and other amino acids) and the grazing rates by harpacytacoid copepods. With respect to grazing, the project will to assess the importance of the presence of toxins, which inhibit grazing as a function of the species of Trichodesmium. In addition, the project will examine the mechanisms of Trichodesmium buoyancy reversals, along with field research on adaptational significance, and the use of isotopic and biochemical "biomarkers" for tracking the fate of Trichodesmium biomass. Finally, Trichodesmium population measurements will be coupled with biooptic measurements with the goal of developing remote sensing algorithms. Overall, the project will provide information to assess critically the inference that Trichodesmium is a quantitatively significant input of new N. This informantion will contribute substantively towards obtaining a complete understanding of the ecology, physiology and biochemistry of planktonic N2 fixers and their role in C and N fluxes in the oceans. ***

Carpenter 9317738该项目继续研究Trichodesmium和其他浮游生物N2固定器的生态，生理和生物化学，在热带北大西洋，W Caribbean，NE＆NW澳大利亚更广泛的地区进行了数次巡航，而不是普罗维斯的努力。一个目的是评估trichodesmium人口丰度和N2固定，并同时评估浮游植物种群丰度和N同化，新的和再生的氮。 物种区别将使用超微结构和NIFH基因测序进行。 这将涉及蛋白质标记和超微结构研究以及分子生物学方法。 下一个目标是确定氮酶活性中DIEL周期性的现象是否是这些人群的共同特征，并进一步研究了该周期性的基础和O2保护的机制。 该项目将继续检查毛t虫C和N的命运，确定不稳定有机物（谷氨酸和其他氨基酸）的释放速率以及甲虫类Copepods的放牧率。 关于放牧，该项目将评估毒素的存在的重要性，毒素的存在抑制了放牧，这是毛trichodesmium物种的函数。 此外，该项目将检查毛d浮标逆转的机制，以及有关适应性意义的现场研究，以及使用同位素和生化的“生物标志物”来跟踪毛d虫生物量的命运。 最后，将三分之一的人口测量与生物型测量结果结合起来，以开发遥感算法。总体而言，该项目将提供信息，以批判性地评估Trichodesmium是新N的定量意义。该信息将有助于完全理解浮游生物N2固定器的生态学，生理学和生物化学及其在海洋中C和N Fluxes中的作用。 ***