Collaborative Research: A Critical Examination of the Relationship Between Marine Phytoplankton Growth Rates and Phosphate Concentrations: Monod or Not

合作研究：对海洋浮游植物生长速率与磷酸盐浓度之间关系的严格检验：莫诺与否

• 批准号: 0647873
• 负责人: Paul Bienfang
• 金额: $ 21.88万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0647873&HistoricalAwards=false
• 关键词: Collaborative; Research; Critical; Examination; Relationship

This project involves the use radioactive phosphorus (33P) as a tracer in chemostat experiments to study the relationship between phosphate concentrations and growth rate in monospecific cultures of marine phytoplankton. For literally decades that relationship has been assumed to be described by the Monod equation, but the inability of colorimetric methods to accurately measure growth-rate-limiting concentrations of phosphate has precluded a rigorous test of this hypothesis. Theoretical analysis indicates that divergence from the Monod equation may be associated with diffusion of the growth-rate-limiting substrate through the boundary layer around the cell. Because the cell quota of limiting nutrient is more variable for phosphorus than nitrogen, it can be shown that the impact of diffusion through the boundary layer on the shape of the growth rate curve is likely to be much greater for phosphorus than for nitrogen. The intellectual merit of the proposed work lies in the use of tracer amounts of 33P to accurately measure phosphate in the nanomolar concentration range and the use of chemostats to provide rigorous control of growth rates. The combination of these methodologies offers by far the best chance of defining the relationship between phosphate concentration and growth rate and hence at last provide a rigorous test of the Monod growth model.The broader impacts of the proposed work include the fact that the research will be a collaborative effort between Louisiana State University (LSU) and the University of Hawaii (UH) and will provide support for a graduate student at each institution. Both LSU and UH are EPSCoR institutions. Dr. Laws has written a textbook titled Mathematical Methods for Oceanographers (John Wiley) and teaches a graduate course at LSU that makes use of that text. The course and text include material on modeling. The results of the proposed work will be integrated into Dr. Laws' course and into future editions of his book and will be submitted for publication in the scientific literature. The broadest impact of the proposed work, however, will be on our understanding of the relationship that controls phytoplankton growth rates in phosphorus-limited systems and the outcome of resource competition among algae. For literally decades that relationship has been assumed to be the Monod equation. This project will use existing the tools to determine whether it is or is not.

该项目涉及在化学仪表实验中使用放射性磷（33p）作为示踪剂，以研究磷酸盐浓度与海洋浮游植物单特异性培养物中的关系。从字面上看，几十年来，已经假定关系是通过monod方程来描述的，但是比色方法无法准确衡量磷酸盐的生长率限制浓度，因此无法对该假设进行严格的检验。理论分析表明，与单体方程的差异可能与通过细胞周围的边界层扩散生长速率限制基板的扩散有关。由于限制养分的细胞配额对于磷比氮的变化更大，因此可以证明，通过边界层扩散对磷的生长速率曲线形状的影响可能要比氮要大得多。拟议工作的智力优点在于使用33p的示踪剂量在纳摩尔浓度范围内准确测量磷酸盐，并使用化学固醇来提供对生长速率的严格控制。这些方法的结合提供了定义磷酸盐浓度和增长率之间关系的最佳机会，因此最终提供了对Monod增长模型的严格测试。拟议工作的更广泛的影响包括该研究将是路易斯安那州州立大学（LSU）与夏威夷大学（UH）之间的协作努力，并将为每个机构提供支持。 LSU和UH都是Epscor机构。 Laws博士写了一本名为《海洋学家数学方法》（John Wiley）的教科书，并在LSU教授一门研究生课程，该课程利用该文本。课程和文字包括建模的材料。拟议工作的结果将纳入Laws博士的课程中，并将其书的未来版本纳入他的书的未来版本中，并将提交科学文献出版。然而，拟议工作的最广泛影响将是我们对控制磷量有限的系统中浮游植物增长率的关系以及藻类资源竞争的结果。从字面上看，几十年来，人们被认为是monod方程。该项目将使用现有工具来确定它是否是。