Collaborative Research: Ecology of microbial mats at seamount associated Fe-rich hydrothermal vent systems

合作研究：海山相关富铁热液喷口系统微生物垫的生态学

• 批准号: 1155756
• 负责人: Craig Moyer
• 金额: $ 60.26万
• 依托单位: Western Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1155756&HistoricalAwards=false
• 关键词: Collaborative; Research; Ecology; microbial; mats

A grand challenge in microbial ecology is to understand what drives the structure of microbial communities. A recently discovered novel class of Proteobacteria, the Zetaproteobacteria, are associated with microbial mats at iron rich hydrothermal vents at submarine volcanoes deep in the ocean. These bacteria only grow using iron as an energy source and fix carbon dioxide. Within iron rich microbial mats, Zetaproteobacteria are the dominant bacterial population; however they are rare in most other deep-sea or marine habitats, suggesting they may be restricted to specific niches characterized by gradients of oxygen and iron. Recent discoveries have expanded their range to fluids collected from deep ocean crust boreholes, iron deposits in coastal saltmarshes, and with steel associated bio-corrosion, demonstrating that marine Zetaproteobacteria are cosmopolitan. A unique property of these marine iron oxidizing bacteria is that they produce morphologically distinct iron oxide structures in the form of filamentous sheaths or stalk-like structures. These structures are easily recognized by light microscopy, and electron microscopy is beginning to reveal subtle differences among them that may be diagnostic of different populations of iron oxidizing bacteria. Another unusual aspect of iron oxidizing bacteria is that they produce large quantities of oxides with relatively little bacterial biomass. As a result, the oxides form a matrix that influences water and nutrient flow in the microbial mats where they grow, and in turn, may influence the growth of other groups of bacteria and archaea that live in the mats. In an ecological context, the PIs believe this makes them a keystone species that form the predominant structural matrix of the mat, and engineer an environment conducive for growth of specific bacterial populations within the mat ecosystem. The PIs propose to use high resolution mat sampling techniques to investigate the architecture of mat ecosystems and couple these with modern molecular methods (i.e., single-cell metagenomics) and geochemical measurements of the vent fluid to couple morphological and functional diversity to phylogenetic and physiological diversity. Because the Zetaproteobacteria are ancient, have unique metabolic and morphological attributes, and appear to be restricted to a well-defined habitat, they offer an interesting model for understanding fundamental ecological concepts that drive microbial diversity and evolution. Broader Impacts: A better understanding of iron oxidizing bacteria that include Zetaproteobacteria is of fundamental interest to scientists interested in areas of earth science and oceanography because they illustrate how microbes can fundamentally influence geochemical cycling and mineral deposition. Furthermore, morphological structures similar to those produced by Zetaproteobacteria can still be identified hundreds of millions (and possibly billions) of years back in the geological record, making them of paleontological, and potentially of exobiological, interest. As knowledge of extant populations grow, it is possible they will also help to inform us of environmental change in past Earth history. A wealth of educational and outreach opportunities will be made possible by this work, including graduate and postdoctoral education, research experiences for undergraduates, and teacher training. In addition the participating scientists are involved in a number of programs to make the general public aware of the process of how scientific research is conducted, and how discoveries of a fundamental nature can ultimately benefit humankind.

微生物生态学中的一个巨大挑战是了解什么推动了微生物群落的结构。最近发现的新型蛋白质类细菌，Zetaproteobacteria与在海洋深处的海底火山的富含铁水热的水热通风口处的微生物垫有关。这些细菌仅以铁作为能源生长并固定二氧化碳。在富含铁的微生物垫中，沸点杆菌是主要的细菌种群。但是，它们在大多数其他深海或海洋栖息地中很少见，这表明它们可能仅限于特定的壁ni，其特征是氧气和铁的梯度。最近的发现将其范围扩大到从深海地壳钻孔，沿海盐泥中的铁矿石以及钢相关的生物腐蚀的液体中，表明海洋Zetaproteobacteria是国际化的。这些海洋铁氧化细菌的独特特性是它们以丝状鞘或茎状结构的形式产生形态上不同的氧化铁结构。这些结构很容易通过光学显微镜识别，电子显微镜开始揭示它们之间的细微差异，这些差异可能是不同种群的铁氧化细菌种群的诊断。铁氧化细菌的另一个不寻常的方面是，它们产生大量的氧化物，细菌生物量相对较少。结果，氧化物形成一个基质，它会影响其生长的微生物垫中的水和养分流，进而可能影响其他生活在垫子中的细菌和古细菌的生长。在生态环境中，PIS认为这使它们成为构成垫子主要结构矩阵的基石物种，并设计一种有利于MAT生态系统中特定细菌种群的生长的环境。 PI提议使用高分辨率MAT采样技术研究MAT生态系统的结构，并将其与现代分子方法（即单细胞元基因组学）和通风液的地球化学测量相结合，以将形态学和功能多样性与系统发育和生理多样性息息。因为Zetaproteobacteria是古老的，具有独特的代谢和形态学特性，并且似乎仅限于定义明确的栖息地，所以它们为理解驱动微生物多样性和进化的基本生态概念提供了一个有趣的模型。更广泛的影响：更好地了解包括Zetaproteobacteria在内的铁氧化细菌是对地球科学和海洋学感兴趣的科学家的基本兴趣，因为它们说明了微生物如何从根本上影响地球化学循环和矿物质沉积。 此外，在地质记录中，仍然可以鉴定出数亿（甚至可能是数十亿）年的数亿（甚至数十亿），使它们具有古生物学，并有可能具有外生物学的兴趣。随着现有人口的知识的增长，他们也可能会帮助我们告知过去地球历史上的环境变化。 这项工作将使大量的教育和外展机会成为可能，包括研究生和博士后教育，本科生的研究经验以及教师培训。此外，参与的科学家参与了许多计划，以使公众意识到科学研究的进行过程以及基本本质的发现最终如何使人类受益。