Evaluating the Environmental Influences on D/H Fractionation in Algal Lipids

评估环境对藻类脂质 D/H 分级的影响

• 批准号: 1027079
• 负责人: Julian Sachs
• 金额: $ 64.55万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1027079&HistoricalAwards=false
• 关键词: Evaluating; Environmental; Influences; Fractionation; Algal

A growing interest in using lipid D/H ratios in biogeochemistry and paleoclimatology has resulted in the application of this new tool advancing more rapidly than our understanding of the processes that control D/H fractionation in algae. A quantitative framework in which to evaluate measured D/H values is still lacking. In this project, researchers at the University of Washington will conduct continuous culture experiments with the marine diatom Thalassiosira psuedonana and the coccolithophorid Emiliania huxleyi at a range of nitrate- and light-limited growth rates, temperatures and salinities to determine how these environmental conditions affect D/H fractionation in lipids. Unlike batch cultures, chemostats permit the evaluation of cells at steady state, under controlled laboratory conditions. These results will be validated with natural populations of phytoplankton in three field experiments. In situ incubation experiments will be conducted in the euphotic zone of subpolar and subtropical North Pacific Ocean sites to evaluate the influence of light- and nutrient-limited growth rate on D/H fractionation in lipids from E. huxleyi. The influence of temperature on D/H fractionation in a natural phytoplankton population will be evaluated by monthly sampling of Lake Washington over the course of a year. D/H fractionation will be determined by comparing the isotopic difference between individual lipids and growth water. Both acetogenic (linear) and isoprenoid (branched) lipids will be analyzed in every experiment. Differences in D/H fractionation in lipids from different biosynthetic pathways will provide the means to formulate and test hypotheses of D/H fractionation mechanisms. Broader Impacts: The environmental education of high school students, undergraduates, women and the public will be advanced by this research. Of 10 lab group members working with the principal investigator during the last year, 4 were women and 3 were undergraduates. Two undergraduates joined the principal investigator's expedition to the Marshall Islands and Kosrae in Summer 2009. The lab website has averaged more than 2000 hits per day in recent months.

对在生物地球化学和古气候学中使用脂质D/H比的兴趣日益增加，这导致了这种新工具的应用，而不是我们对控制藻类中D/H分馏的过程的理解要快。仍缺乏评估测得的D/H值的定量框架。在该项目中，华盛顿大学的研究人员将通过海洋硅藻thalassira psuedonana和Coccolithophorid emiliania huxleyi进行连续的培养实验，以一系列硝酸盐和光线限制的生长速率，温度和盐度，以确定这些环境条件如何影响d/h bractions lipidss in lipidss。与批处理培养物不同，化学固醇允许在受控实验室条件下评估稳态的细胞。在三个田间实验中，这些结果将通过浮游植物的天然种群进行验证。原位孵育实验将在亚热带和亚热带北太平洋地点的舒适区域进行，以评估光和养分受限的生长速率对Huxleyi E. huxleyi脂质中D/H分馏的影响。温度对天然浮游植物种群中D/H分馏的影响将在一年的时间内每月对华盛顿湖进行采样。 D/H分馏将通过比较单个脂质和生长水之间的同位素差来确定。在每个实验中，都将分析乙酸（线性）和异普尼（分支）脂质。来自不同生物合成途径的脂质中D/H分馏的差异将提供表达和检验D/H分级机制的假设的手段。更广泛的影响：这项研究将推动高中生，本科生，妇女和公众的环境教育。去年，在与主要研究人员合作的10名实验室小组成员中，有4名是妇女，有3名是本科生。两名大学生在2009年夏季加入了首席调查员前往马歇尔群岛和科斯拉的探险。实验室网站近几个月来平均每天超过2000次命中。