Microbial Cycling of Dissolved Organic Phosphorus in the Oligotrophic North Atlantic: The Nucleic Acid Connection

寡营养北大西洋溶解有机磷的微生物循环：核酸联系

• 批准号: 9019415
• 负责人: James Ammerman
• 金额: $ 16.76万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-03-01 至 1993-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9019415&HistoricalAwards=false
• 关键词: Microbial; Cycling; Dissolved; Organic; Phosphorus

Despite a major focus on nitrogen as the limiting nutrient in marine ecosystems, there is evidence that in some marine environments, especially the vast oligotrophic central gyres, that phosphate appears to be refractory and potentially limiting, although a fraction of the phosphate pool does appear to turn over rapidly. Dissolved nucleic acids will be examined as a model component of this rapidly-cycling fraction, because many of the breakdown rates and the concentrations of the resulting intermediates can be measured. These parameters will be measured by a combination of fluorometric, isotopic, and spectrophotometric techniques and will be compared to parallel measurement of the major phosphate pools and fluxes. This project will test the hypotheses that microbial breakdown of dissolved nucleic acids is both: 1) a quantitatively important pathway, and 2) a model pathway for the cycling of labile dissolved organic phosphate in the oligotrophic North Atlantic. This research will further our understanding of the cycling of dissolved organic phosphate, a suite of compounds with potentially global importance to marine primary production. Furthermore, this research will lead to insights into microbial processes of biopolymer and monomer breakdown. Finally, since dissolved nucleic acids are genetic material and also significant reservoirs of dissolved organic carbon and nitrogen, these studies will increase our knowledge of environmental gene transfer and of dissolved organic carbon and nitrogen cycling in the environment.

尽管人们主要关注氮作为海洋生态系统中的限制性营养物质，但有证据表明，在一些海洋环境中，特别是在广袤的少营养中心环流中，磷酸盐似乎是难溶的，具有潜在的限制性，尽管磷酸盐池中的一小部分似乎确实很快就会周转。溶解的核酸将作为这种快速循环组分的模型成分进行检查，因为许多分解速率和所产生的中间产物的浓度都可以测量。这些参数将通过荧光、同位素和分光光度技术的组合进行测量，并将与主要磷酸盐池和熔剂的平行测量进行比较。该项目将检验微生物分解溶解核酸的假设：1)在数量上重要的途径，2)在营养稀少的北大西洋中不稳定的溶解有机磷循环的模型途径。这项研究将进一步加深我们对溶解有机磷循环的理解，溶解有机磷是一系列对海洋初级生产具有潜在全球重要性的化合物。此外，这项研究将有助于深入了解生物聚合物和单体分解的微生物过程。最后，由于溶解核酸是遗传物质，也是溶解有机碳和氮的重要储存库，这些研究将增加我们对环境基因转移和环境中溶解有机碳和氮循环的了解。