Diazotrophic Cyanobacteria: An Underestimated Source of NewNitrogen in the Oligotrophic Oceans

固氮蓝藻：寡营养海洋中被低估的新氮来源

• 批准号: 8900588
• 负责人: John Waterbury
• 金额: $ 18.58万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8900588&HistoricalAwards=false
• 关键词: Diazotrophic; Cyanobacteria; Underestimated; Source; NewNitrogen

This research program is a systematic reassessment of the role of dinitrogen fixation in the upper layers of the open ocean using diazotrophic cyanobacteria. Nitrogen fixation in the open ocean is potentially a major source of nitrogen in seawater, and one of the few ways in which atmospheric nitrogen is transferred to the sea. A procedural redesign of the actylene reduction assay for nitrogenase activity will be undertaken so that unconcentrated seawater samples can be used for study. The new technique has to be perfected, tested and calibrated in the laboratory first. Second the technique will be field tested in local waters near Woods Hole and in a two week field study in the Sargasso Sea. %%% The fixation of nitrogen by marine organisms in the open ocean is one of the few pathways by which nitrogen in the atmosphere is transferred to the sea. Because nitrogen is the fertilizing element most often in short supply in the sea, its concentration often determines the amount of primary production that can take place in the open ocean. In areas of the ocean where nitrogen is especially scarce, microorganisms have been found that convert atmospheric nitrogen to their own tissues. The methods used for measuring nitrogen fixation are old and have problems. An attempt will be made to develop and test new methods that are more sensitive and less invasive than previous approaches.

这项研究计划是一个系统的重新评估的作用， 在开阔海洋上层的固氮作用， 固氮蓝藻 开阔海洋中的氮固定 可能是海水中氮的主要来源， 大气中的氮转移到大气中的几种方式， 海 乙炔还原测定法的程序重新设计 固氮酶活性将进行， 海水样本可作研究之用。 新技术必须 首先在实验室进行完善、测试和校准。 其次，这项技术将在附近的当地沃茨进行实地测试。 伍兹霍尔和在马尾藻海为期两周的实地研究。 %%% 海洋生物对氮的固定作用 大气中的氮是少数几个 转移到海上。 因为氮是 在海洋中最经常短缺的元素，其浓度 往往决定了初级生产力的数量， 在开放的海洋中。 在海洋中氮含量很高的区域 特别是稀有的，已经发现微生物， 空气中的氮会进入它们自己的组织 所用的方法 测量固氮是旧的，有问题。 一个 将尝试开发和测试新的方法， 比以前的方法更敏感，侵入性更小。