Groundwater Ecosystems: The Interdependence of Microbial Mineral Weathering and Population Diversity

地下水生态系统：微生物矿物风化和种群多样性的相互依存jennifer A. Roberts, David Graham, and William D. picky, University of Kansas, Rachel O'Brien， Allegheny college细菌参与矿物风化现在已被接受，甚至是地下地球化学的预期组成部分。在超过3公里的深度和接近100摄氏度的温度下发现了微生物，越来越多的证据表明，这些生物的生化功能可能是许多低温矿物风化反应背后的驱动力。然而，科学界才刚刚开始记录微生物催化的反应，因此出现了许多问题。负责的生物是否从风化反应中受益？矿物溶解如何影响定植微生物群落的生物多样性？这种风化反应很可能从地质时代开始就在起作用。因此，了解这些现象，以及相关的生物，不仅提供了环境风化现象的直接图像，而且可能为微生物进化和控制地下生物多样性的因素提供见解。这项工作有两个目标。首先，我们将利用来自六个不同地下水生态系统（温带阔叶林、热带森林、热带砍伐草地、温带高草草原、北方湿地和热带湿地）的原生群落，研究营养驱动和金属抑制的合成硅酸盐相和天然硅酸盐相的微生物风化。这项工作的结果将证明微量浓度的营养物质和金属在固相如何影响微生物风化反应。其次，我们将在一组选定的地下水生态系统中描述微生物活动、群落组成和生物多样性。根据这一特征，我们将研究由于营养和含金属硅酸盐的引入和风化而导致的微生物种群演替。该项目的结果将有助于深入了解硅酸盐结合的营养物质和金属对微生物风化的影响，以及矿物组成和风化反应如何影响各种地下水生态系统地表定植微生物群落的生物多样性。我们的研究还将阐明现代微生物风化过程是如何起作用的，反过来，可能有助于确定地质时期的关键过程。

Groundwater ecosystems: The interdependence of microbial mineral weathering and population diversityJennifer A. Roberts, David Graham, and William D. Picking, University of Kansas Rachel O'Brien, Allegheny CollegeParticipation of bacteria in mineral weathering is now an accepted, even expected component of subsurface geochemistry. Microorganisms have been found at depths exceeding 3 kilometers and at temperatures approaching 100C, and there is growing evidence that the biochemical functions of these organisms may be the driving force behind many low temperature mineral-weathering reactions. The scientific community has only begun documenting microbial-catalyzed reactions, however, and many questions arise. Do the responsible organisms benefit from weathering reactions? How does mineral dissolution affect biodiversity in colonizing microbial communities? Such weathering reactions have likely been operative since the beginning of geologic time. Therefore, understanding such phenomena, and the associated organisms, not only provides an immediate picture of ambient weathering phenomena, but might also provide insights into microbial evolution and factors that control subsurface biodiversity. There are two goals for this work. First, we will investigate nutrient-driven and metal-inhibited microbial weathering of synthetic and natural silicate phases using native consortia from a from six distinct groundwater ecosystems (temperate hardwood forest, tropical forest, tropical clearcut grassland, temperate tallgrass prairie, boreal wetland, and a tropical wetland). The results of this work will demonstrate how trace concentrations of nutrients and metals in the solid phase influence microbial weathering reactions. Second, we will characterize microbial activity, community composition, and biodiversity in a select group of groundwater ecosystems. Following this characterization we will examine the microbial population succession that results from the introduction and weathering of nutrient- and metal-bearing silicates.Results from this project will lend insight into the influence of silicate-bound nutrients and metals on microbial weathering, and how mineral composition and weathering reactions impact the biodiversity of the surface colonizing microbial community for a variety of groundwater ecosystems. Our investigations will also elucidate how modern microbial weathering processes function, and in turn, may help identify key processes through geologic time.