SGER: Microorganisms in Sub-ice Sediments from The Western Antarctic Ice Sheet, Ice Stream C

南极西部冰盖(WAIS)的冰流被认为在其底部有未冻结的、水饱和的沉积物。北极冰川和高山冰川下方类似的水-岩-冰界面已被证明拥有丰富的微生物群落，这些微生物群落通过其代谢活动影响这些环境的地球化学。如果微生物群落存在于WAIS冰流下的沉积物中，它们将与外部环境影响隔离至少2万年。本项目将重点研究从冰流C之下(WAISC)采集的独特沉积物岩芯中微生物的分子特征，并提出两个主要假设：1)WAISC沉积物中存在独特的微生物群落；2)WAISC沉积物微生物群落在接近原位的条件下是活跃的。WAISC的沉积物微生物将与其他冰下和海洋沉积系统的微生物进行比较，并将分离出具有地球化学相关代谢活动的微生物。将与其他实验室协调进行孔隙水化学和沉积物物理参数的工作，以确定这一独特的栖息地。由此产生的数据应该能够深入了解微生物种群动态和在这个寒冷、黑暗和与世隔绝的环境中的生存机制。此外，这项研究将扩大我们对微生物群落结构和功能的了解，包括南极冰下环境，并可能为微生物在极端的“雪球地球”事件和天体生物学中可能发挥的作用提供见解。该项目将支持一个跨学科研究项目中一名博士后学者和一名本科生的培训。PI将在本科生入门课程和研究生课程中使用该项目的概念。数据、图像和其他材料将通过一个公开的网站提供。

Ice streams of the Western Antarctic Ice Sheet (WAIS) are thought to have unfrozen, water-saturated sediments at their base. Similar water-rock-ice interfaces beneath Arctic and alpine glaciers have been demonstrated to house abundant microbial communities which, through their metabolic activities, affect the geochemistry of these environments. If microbial communities are present in the sediments beneath the WAIS ice streams, they will have been isolated from outside environmental influences for a minimum of 20,000 years. This projectwill focus on the molecular characterization of microbes in a unique sediment core collected from beneath Ice Stream C, WAIS (WAISC) with two main hypotheses: 1) There is a unique microbial community present in the WAISC sediments, and 2) The WAISC sediment microbial community is active at near in situ conditions. The WAISC sediment microbes will be compared to microbes from other subglacial and marine sedimentary systems and microbes with geochemically-relevant metabolic activitie will be isolated. Work will be coordinated with other laboratories for pore water chemistry and sediment physical parameters to define this unique habitat. Resulting data should provide insight into microbial population dynamics and survival mechanisms in this cold, dark, and isolated environment. Furthermore, this study will expand our knowledge of microbial community structure and function to include Antarctic subglacial environments and may provide insights into possible roles of microbes during extreme "Snowball Earth" events and astrobiology. This project will support the training of a postdoctoral scholar and an undergraduate student in an interdisciplinary research project. The PI will use concepts from this project in both an introductory undergraduate course and a graduate level course. Data, images, and other materials will be made available through a publicly available web site.