Environmental Genomics and Microbial Observatories: Analysis of Genetic Variability, Gene Content, and Genomic Potential in Uncultivated Marine Picoplankton

微浮游生物是一种小的浮游微生物，直径从0.2毫米到2.0毫米不等，是世界海洋中最丰富的细胞生物。在全世界范围内，这些微生物的浓度从10,000到1,000,000个细胞/毫升不等，估计消耗了海洋初级生产力的20- 50%。浮游微生物在生物化学上也是多才多艺的，它们介导了海洋生物圈中发生的碳、氮和硫的大多数关键化学转化。然而，人们对这些具有全球重要性的微生物的生物学、生理学和遗传学知之甚少，这主要是因为一些最主要的类型已经抵制了培养。该项目将利用新开发的基因组技术来描述世界性和丰富的，但未经养殖的浮游生物物种。具体来说，该项目将对天然浮游微生物制备的大型插入染色体DNA文库进行测序、注释和分析。这些数据将提供迄今无法获得的关于未培养微生物的信息，这些微生物具有高丰度和无处不在的全球分布。浮游微生物的基因组组织、基因含量和功能蛋白分布将首次成为可能。此外，开发的新方法和工具将大大推进和扩展目前微生物观测站在海洋和其他不同环境中的工作。我们的方法将大大增加对未培养微生物的一般了解，这些微生物在很大程度上调节了世界海洋中能量和物质的流动。这项工作产生的数据也将为构建DNA微阵列提供必要的基础，用于高通量监测多样性和基因表达，全球重要的海洋微生物物种。最终，本研究中开发的方法将为任何地点重要微生物群落的变异性、活性和意义提供详细的见解。

Picoplankton, small planktonic microorganisms ranging in diameter from 0.2 to 2.0 mm, are the most abundant cellular organisms in the world's oceans. At concentrations of ranging from 10,000 to 1,000,000 cells /ml worldwide, these microorganisms consume an estimated 20-50 % of marine primary productivity. Planktonic microbes are also biochemically versatile, mediating most of the key chemical transformations of carbon, nitrogen, and sulfur that occur in the oceanic biosphere. However, very little is known about the biology, physiology and genetics of these globally important microbes - mainly because some of the most dominant types have resisted cultivation. This project will characterize cosmopolitan and abundant, but uncultured, picoplankton species using newly developed genomic technologies. Specifically, the project will sequence, annotate and analyze large insert chromosomal DNA libraries prepared from naturally occurring planktonic microorganisms. These data will provide hitherto unavailable information on uncultured microorganisms that have a high abundance and ubiquitous global distribution. Genomic organization, gene content, and functional protein distributions of planktonic microbes will become available for the first time. Furthermore, the new approaches and tools developed will significantly advance and extend current Microbial Observatory efforts in the ocean and other diverse environments. Our approach will significantly increase the general understanding of uncultivated microorganisms that largely mediate the flux of energy and matter in the world's oceans. Data resulting from this effort will also provide the foundation necessary for constructing DNA microarrays, designed for high throughput monitoring of the variability and gene expression of diverse, globally significant marine microbial species. Ultimately, the approaches developed in this research will provide detailed insight into the variability, activity, and significance of important microbial communities from any site.