Methods for the species-specific analysis of photosynthesis and top-down vs. bottom-up control in marine phytoplankton

海洋浮游植物光合作用的物种特异性分析以及自上而下与自下而上控制的方法

• 批准号: 290359337
• 负责人: Dr. Maike Piepho
• 金额: --
• 依托单位: Department of Marine Microbiology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/290359337?language=en
• 关键词: Methods; species; specific; analysis; photosynthesis

Phytoplankton builds the basis of all aquatic food webs. Species in an algal community differ in abundance and photosynthetic performance and production. These differences can have an essential effect on energy transfer in the food web. Abundant species with low production rates are possibly not grazed by zooplankton and thus do not contribute to energy transfer in the food web. In contrast, high production rates of less abundant species could indicate that they are grazed preferentially. Therefore, they might be of higher importance for energy transfer in the food web than abundant species.To test these hypotheses, methods for species-specific analysis of phytoplankton are to be tested in the Royal Netherlands Institute for Sea Research (NIOZ) in Yerseke, The Netherlands. Flowcytometry allows a fast characterization of the phytoplankton community (cell numbers and fluorescence as a measure of photosynthetic capacity), but only a coarse differentiation of algal groups. Single-cell analysis with a combination of microscope and pulse-amplitude modulation (PAM) fluorometry is much more detailed. Species can be determined accurately and their photosynthetic performance can be measured at the same time. This method is time-consuming and allows only for the measurement of a limited number of cells. A combination of flowcytometry and microscopy-PAM seems promising to test the hypotheses. The three months stay at the NIOZ in Yerseke will be used for optimizing the described methods for the single-cell analysis of phytoplankton. Afterwards, the phytoplankton community in the North Sea is to be characterized. Following the stay, the acquired knowledge will applied in a planned research project that will deal with energy transfer in the food web of the North and Baltic Sea.

浮游植物构建了所有水生食物网的基础。藻类群落中的物种在丰度、光合作用性能和产量方面存在差异。这些差异可能对食物网中的能量转移产生重要影响。生产力低下的丰富物种可能不被浮游动物吃草，因此对食物网中的能量转移没有贡献。相反，数量较少的物种的高生产率可能表明它们被优先放牧。因此，它们对于食物网中的能量转移可能比丰富的物种更重要。为了检验这些假设，浮游植物的物种特异性分析方法将在荷兰耶尔瑟克的荷兰皇家海洋研究所 (NIOZ) 进行测试。流式细胞术可以快速表征浮游植物群落（细胞数量和荧光作为光合能力的衡量标准），但只能粗略区分藻类。结合显微镜和脉冲幅度调制 (PAM) 荧光测定法进行的单细胞分析要详细得多。可以准确地确定物种，同时可以测量其光合性能。这种方法非常耗时，并且只能测量有限数量的细胞。流式细胞术和显微镜-PAM 的结合似乎有望检验这些假设。在 Yerseke NIOZ 的三个月停留时间将用于优化所描述的浮游植物单细胞分析方法。随后，将对北海浮游植物群落进行表征。停留后，所获得的知识将应用于计划中的研究项目，该项目将处理北海和波罗的海食物网中的能量转移。