Formation of Dissolved Free Amino Acids in Seawater and Its Coupling to Uptake

海水中溶解游离氨基酸的形成及其与吸收的耦合

• 批准号: 8711132
• 负责人: Jed Fuhrman
• 金额: $ 8.83万
• 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: 1987
• 资助国家: 美国
• 起止时间: 1987-11-15 至 1988-11-17
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8711132&HistoricalAwards=false
• 关键词: Formation; Dissolved; Free; Amino; Acids

This renewal proposal from Dr. Fuhrman is for an extension of studies on dissolved free amino acids (DFAAs), with new emphasis on the open sea. The DFAAs are important sources of organic C and N, and represent excellent models of biologically- labile dissolved organic matter (DOM). DOM flux is now known to be a major part of the marine C and N cycles. Recent work demonstrating very rapid turnover of small DFAA pools has shown a need to revise previous ideas in this area. This proposal includes extensive studies of DFAA turnover, flux, and availability in the oligothrophic and deep ocean, from which reliable data are sparse. Other proposed work includes measuring DFAA release from zooplankton fecal pellets, the microbial responses to sudden DFAA enrichment as might be found in "enriched microzones," algal assimilation of DFAAs, ammonium regeneration from DFAAs, and degradation of peptides and proteins. In addition to the usual tritiated tracers, for some of this work the fate of the amino acid nitrogen will be traced with the short-lived isotope N-13. This isotope has a very high specific activity, so it can be added at true trace levels with great sensitivity. But due to its brief useful lifetime (ca. 90 min.), samples must be transported to the cyclotron, so for these experiments the use of a helicopter to sample offshore waters is required.

福尔曼医生提出的延期申请 溶解游离氨基酸（DFAA）的研究，新的 重点是公海。 DFAAs是重要的 有机碳和氮，并代表了生物学的优秀模型- 不稳定溶解有机物（DOM）。 DOM通量现在已知 是海洋碳氮循环的重要组成部分。 最近的工作 小DFAA池的快速周转表明， 需要修改这一领域以前的想法。 这项建议 包括对DFAA营业额、流量和 在寡养和深海中的可用性， 可靠的数据很少。 其他建议的工作包括测量 浮游动物粪便颗粒释放DFAA，微生物 对DFAA突然富集的反应， “富集微区”，藻类同化DFAAs，铵 从DFAA再生，以及肽的降解， proteins. 除了通常的氚化示踪剂，对于一些 这项工作的氨基酸氮的命运将被追踪 短寿命的同位素N-13 这种同位素具有非常高的 特定活性，因此可以以真正的微量水平添加， 非常敏感。 但由于其短暂的使用寿命（约。90 min.），样品必须被运送到回旋加速器，所以对于这些 实验使用直升机对近海沃茨进行采样， 必需的.