Physiological Ecology of Marine Cyanobacterial Communities

海洋蓝藻群落的生理生态学

• 批准号: 9633111
• 负责人: Brian Palenik
• 金额: $ 37万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9633111&HistoricalAwards=false
• 关键词: Physiological; Ecology; Marine; Cyanobacterial; Communities

9633111 PALENIK This project will use an integrated multi-investigator approach to determine the extent and causes of cyanobacterial biodiversity in the marine environment. The project hypothesis is that stratification in the oceans, although often transient, has led to the development of a limited number of physiologically and genetically distinct and recognizable groups ("species") of cyanobacteria specifically adapted to the high light, low nutrient mixed layer and others adapted to the higher nutrient, low light life below it. Even this simple scenario is much more complex than the current oceanographic paradigm. There is currently little knowledge of the spatial or temporal variations in natural cyanobacterial diversity, and we can only guess at the factors that may be driving it. The importance this diversity may have in determining oceanographic rate processes, such as in situ growth or carbon fixation rates, is unknown, and its role cannot really be addressed until we understand the extent and patterns of cyanobacterial diversity. This project is the first step in being able to assay the growth rates and metabolic activities of individual physiological or genetic types. Since similar genetic and physiological processes probably also occur in other groups of phytoplankton, these questions are of general significance to biological oceanography. This project will also begin to look at not just the number of microbial "species" in an environment, but why that number? The microbiota of the marine environment are coming to be seen as remarkably diverse, and an understanding of the processes underlying this diversity will best be gained by examining the diversification of a related group of microorganisms in detail in relationship to physiochemical parameters. The marine environment is probably the best place to begin to understand these questions because there is also considerable experience in understanding the physiochemical gradients surrounding the o rganisms. RNA polymerase gene sequences from strains and bulk community samples, flow cytometric analyses, pigment analyses, antibody assays for motile Synechococcus and other strains, strain isolation techniques, physiological studies on nitrogen and light utilization, and physiochemical data will be the initial set of tools we will bring to these problems, with others under development. Three sites in the oligotrophic boundary of the Southern California Bight will be sampled at several depths for two consecutive years at the same season to ensure the reproducibility of our conclusions. A third cruise will focus on characterizing the same sites at a different season in order to begin to explore temporal variations in diversity. This focused sampling effort will ensure a tractable approach to understanding the importance of cyanobacterial diversity to marine ecosystems. ***

9633111 PALENIK该项目将采用集成的多入侵者方法来确定海洋环境中蓝细菌生物多样性的程度和原因。该项目的假设是，海洋中的分层虽然通常是短暂的，但却导致了有限数量的生理和遗传区别和可识别的组（“物种”）的蓝细菌（物种”），专门适用于高光，低营养混合层，而其他则适应了较高的营养素，低于其下方的较低的阳光，低光寿命。即使是这种简单的场景，也比当前的海洋范式要复杂得多。目前，对天然蓝细菌多样性的空间或时间变化知之甚少，我们只能猜测可能驱动它的因素。这种多样性在确定海洋学速率过程（例如原位增长或碳固定率）中的重要性尚不清楚，直到我们了解蓝细菌多样性的程度和模式之前，才真正解决其作用。该项目是能够分析个人生理或遗传类型的增长率和代谢活性的第一步。由于类似的遗传和生理过程也可能发生在其他浮游植物群中，因此这些问题对生物海洋学具有一般意义。 该项目还将不仅开始考虑环境中的微生物“物种”的数量，而且为什么这一数字呢？海洋环境的微生物群将被视为非常多样化，并且最好通过研究与生理化学参数的详细介绍相关微生物的多样化来获得对这种多样性的过程的理解。海洋环境可能是开始理解这些问题的最佳场所，因为在理解围绕O人的理化学梯度方面也有很多经验。来自菌株和大量社区样本的RNA聚合酶基因序列，流式细胞术分析，色素分析，运动型合子的抗体测定和其他菌株，应变隔离技术，氮的生理研究，对氮气和光利用率，轻利用以及生理化学数据的最初构成工具，这些工具将带来这些问题。南加州海湾贫营养边界的三个地点将在同一季节连续两年进行多个深度进行采样，以确保我们的结论的可重复性。第三次巡游将着重于在不同季节表征相同的站点，以开始探索多样性的时间变化。这项集中的抽样工作将确保一种可以理解蓝细菌多样性对海洋生态系统的重要性的方法。 ***