Collaborative Research: Biology and Ecology of Newly Discovered Diazotrophs in the Open Ocean

合作研究：公海中新发现的固氮生物的生物学和生态学

• 批准号: 0425583
• 负责人: Joseph Montoya
• 金额: $ 43.06万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0425583&HistoricalAwards=false
• 关键词: Collaborative; Research; Biology; Ecology; Newly

The productivity of the oceans is limited by the availability of nutrients, which hasimplications for the fluxes of carbon between the atmosphere and oceans. In a previousaward the PIs found that previously unrecognized N2-fixing unicellular cyanobacteriaare active and abundant in oligotrophic oceans. This finding has important implicationsfor nitrogen cycling in the oceans and for the role of "new" nitrogen in carbon fixation.The PIs will address three major issues: First, there are at least two distinct groups ofcyanobacteria that appear to be separated in space and time, due to unknownecological variables. Second, the geographic distribution and factors controlling thedistribution are unknown, so it is not clear how these organisms should be included inbiogeochemical models. Finally, one of the groups of cyanobacteria appears to fix N2during the day, which revives the enigma of simultaneous nitrogen fixation andphotosynthesis that was previously limited to discussions of Trichodesmium.

海洋的生产力受到营养物质可获得性的限制，这对大气和海洋之间的碳通量产生了影响。在先前的研究中，PI发现以前未被识别的固定N2的单细胞蓝藻在贫营养海洋中活跃且丰富。这一发现对海洋中的氮循环和“新”氮在碳固定中的作用具有重要意义。PI将解决三个主要问题：首先，由于未知的生态学变量，至少有两个不同的蓝藻群体在空间和时间上似乎是分开的。其次，地理分布和控制分布的因素是未知的，因此不清楚这些生物应该如何包括在地球化学模型中。最后，其中一组蓝细菌似乎在白天固定N2，这恢复了以前仅限于讨论束丝藻的同时固氮和光合作用之谜。