Collaborative Research: Biocomplexity of Aquatic Microbial Systems: Relating Diversity of Microorganisms 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: 9981424
• 负责人: George Jackson
• 金额: --
• 依托单位: Texas A&M Research Foundation
• 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 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9981424&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：合作研究：水生微生物系统的生物复杂性——将微生物多样性与生态系统功能联系起来元素的微生物生物地球化学循环调节动态环境，其中不同元素的循环通过微生物的生理学联系起来。虽然通过物理/化学方法对净转化进行测量和建模可以获得一定程度的理解，但这些方法必然依赖于对所涉及的各种功能组（行会）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，微生物世界在各个层面上都包含巨大的多样性和复杂性：单个生物体内功能基因的冗余和重复；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；不同生物体之间存在巨大的遗传多样性，显然在单个群落内发挥着相同的生物地球化学功能；不同群落的物种组成存在很大差异，但显然表现同样出色。该项目的目标是研究微生物群落的复杂性与一系列生物和生态尺度的物理/化学环境之间的功能关系。此前，此类分析在技术上受到限制，因为无法同时分析大量样本的大量基因和系统发育型。利用基因阵列技术，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将 DNA 芯片技术应用于环境中“外来”（即不具有生物医学重要性）过程和生物体基因表达的第一步。基因阵列以及全套生态系统过程测量将沿着横跨从切萨皮克湾内陆水域到马尾藻海的富营养-寡营养梯度的横断面部署。实验和功能基因研究将重点关注碳和氮循环中的关键转变（固碳、固氮、硝化、反硝化、尿素同化）。行会的多样性将根据生态系统功能进行解释，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实地研究外，合作科学家小组还将利用中宇宙进行微扰实验。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养分流动，并评估与负责主要氮和碳途径的微生物群内冗余变化相关的稳定性或不稳定程度。