Collaborative Research: Biocomplexity of Aquatic Microbial Systems: Relating Diversity of Microorganosms to Ecosystem Function

合作研究：水生微生物系统的生物复杂性：微生物多样性与生态系统功能的关系

• 批准号: 9981437
• 负责人: Jonathan Zehr
• 金额: $ 62万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9981437&HistoricalAwards=false
• 关键词: Collaborative; Research; Biocomplexity; Aquatic; Microbial

BIOCOMPLEXITY: Collaborative Research: Biocomplexity of aquatic microbial systems -- relating diversity of microorganisms to ecosystem functionMicrobial biogeochemical cycling of the elements regulates a dynamic environment in which the cycles of different elements are linked through the physiology of microorganisms. While a certain degree of understanding can be gained through physical/chemical approaches to measurement and modeling of the net transformations, these approaches necessarily rely on gross simplifications about the role and regulation of the various functional groups (guilds) involved. Recent advances in molecular microbial ecology have shown the microbial world to contain immense diversity and complexity at every level: redundancy and duplication of functional genes within a single organism; molecular diversity among functional genes that encode the same process in different organisms; large genetic diversity among different organisms apparently engaged in the same biogeochemical function within single communities; great variability in the species composition of different communities that apparently perform equally well. The goal of this project is to investigate the functional relationship between complexity in microbial communities and the physical/chemical environment at a range of biological and ecological scales. Previously, such analysis was technologically limited by the inability to assay large numbers of samples simultaneously for a large number of genes and phylotypes. Using gene array technology, the researchers will be able to detect the distribution and differential expression of functional genes in natural systems. The results of this study will constitute the first step towards application of DNA chip technology for gene expression of "exotic" (i.e., not of biomedical importance) processes and organisms in the environment. The gene arrays, along with a full suite of ecosystem process measurements, will be deployed along a transect that spans the eutrophic - oligotrophic gradient from the inland waters of the Chesapeake Bay out to the Sargasso Sea. Experiments and functional gene studies will focus on key transformations in the carbon and nitrogen cycles (C fixation, N fixation, nitrification, denitrification, urea assimilation). The diversity of guilds will be interpreted in terms of ecosystem function, assessed using geochemical data and tracer experiments. In addition to field studies designed to investigate and dissect the natural system, the group of collaborating scientists will also perform perturbation experiments using mesocosms. The goal of these experiments is to determine how microbial species diversity affects the major energy and nutrient flows within ecosystems, and to assess the degree of stability or instability associated with changes in redundancy within guilds of microorganisms responsible for major nitrogen and carbon pathways.

生物复杂性：协作研究：水生微生物系统的生物复杂性 - 将微生物的多样性与生态系统功能功能型生物地球化学循环相关联，调节了动态环境，其中不同元素的循环通过微生物的生理学将不同元素的循环链接在一起。尽管可以通过物理/化学方法来测量和建模净转换来获得一定程度的理解，但这些方法必定依赖于有关各种官能团（guilds）的作用和调节的总体简化。分子微生物生态学的最新进展表明，微生物世界在各个级别都包含巨大的多样性和复杂性：单个生物体中功能基因的冗余和重复；在不同生物体中编码相同过程的功能基因之间的分子多样性；不同生物体之间的巨大遗传多样性显然参与了单个社区的同一生物地球化学功能；显然表现良好的不同社区物种组成的差异很大。该项目的目的是研究微生物群落中的复杂性与一系列生物学量表的物理/化学环境之间的功能关系。以前，这种分析在技术上受到无法同时分析大量基因和系统型的大量样品的限制。使用基因阵列技术，研究人员将能够检测自然系统中功能基因的分布和差异表达。这项研究的结果将构成用于应用DNA芯片技术在环境中的“异国情调”（即不是生物医学重要性）过程的基因表达的第一步。基因阵列以及一套完整的生态系统过程测量值将沿横断面部署，该样带从切萨皮克湾的内陆水域跨越富营养的 - 贫营养梯度到萨尔加索海。实验和功能基因研究将集中于碳和氮循环的关键转化（C固定，N固定，硝化，硝化，硝化，尿素同化）。公会的多样性将根据生态系统功能来解释，并使用地球化学数据和示踪剂实验进行评估。除了旨在调查和剖析自然系统的现场研究外，合作的科学家组还将使用中心进行扰动实验。这些实验的目的是确定微生物物种多样性如何影响生态系统内的主要能量和营养流，并评估与负责主要氮气和碳途径的微生物行会内冗余变化相关的稳定性或不稳定性的程度。