Life in Ice: Probing Microbial Englacial Activity through Time

冰川冰芯就像一座历史博物馆，提供了过去气候条件的详细记录。除了温度、化学和气体成分等时间记录外，冰还为微生物和其他生物材料的保存提供了一个独特的环境。这些微生物为我们了解在地球冰冻圈和其他冰冷的行星体中生存所必需的生理能力提供了宝贵的见解，但我们对它们知之甚少。该奖项支持对冰中微生物活动的基础研究，并直接支持2015年美国国家科学院、工程院和医学院报告《美国国家科学基金会投资南极和南大洋研究的战略愿景》中确定的有关南极生物群的主要研究重点。这项工作的更广泛的影响是，它将与古气候和生物学领域的研究人员相关。它将支持两名早期职业研究人员，一名研究生和一名本科生，他们将进行实验室分析，参与推广活动，在科学期刊上发表论文并出席会议。这项工作将使用先前收集的冰芯来研究从全新世到末次冰盛期的冰川微生物活动，这些冰芯来自南极洲泰勒冰川的蓝色冰区。该提案确定了在以下方面做出重大贡献：1)投资南极生物如何进化和适应不断变化的环境；2)了解微生物如何改变冰芯中与古记录相关的气体和微量元素信息的保存；3)识别冰芯中的微生物生命及其与尘埃沉积事件相关的活动。最近开发的两种互补技术（生物正交非规范氨基酸标记和氘同位素探测）结合拉曼共聚焦显微光谱将用于评估和量化冰中的微生物活性。在项目的第一阶段，这些方法将使用美国国家科学基金会冰芯设施中可用的脱氮冰芯进行优化。在第二阶段，将对泰勒冰川的时间序列冰芯进行地球化学和微生物活动分析。研究结果将提供一个全面的视角，包括其代谢多样性和活性，以及地球化学参数对不同气候时期微生物组合的影响。由于缺乏关于冰川微生物群落的信息，本研究的结果将具有特别的意义。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Glacial ice cores serve as a museum back in time, providing detailed records of past climatic conditions. In addition to chronological records such as temperature, chemistry and gas composition, ice provides a unique environment for preserving microbes and other biological materials through time. These microbes provide invaluable insight into the physiological capabilities necessary for survival in the Earth’s cryosphere and other icy planetary bodies, yet little is known about them. This award supports fundamental research into the activity of microbes in ice, and directly supports major research priorities regarding Antarctic biota identified in the 2015 National Academies of Sciences, Engineering, and Medicine report, A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research. The broader impacts of this work are that it will be relevant to researchers across paleoclimate and biological fields. It will support two early career researchers, a graduate and an undergraduate student who will conduct laboratory analyses, participate in outreach activities, publish papers in scientific journals and present at conferences. This work will use previously collected ice cores to investigate englacial microbial activity from the Holocene back to the Last Glacial Maximum from the blue ice area of Taylor Glacier, Antarctica. The proposal identified making significant contributions to 1) investing how Antarctic organisms evolve and adapt to changing environment, 2) understanding how microbes alter the preservation of paleorecord-relevant gas and trace element information in ice cores, and 3) identifying microbial life in cores and their activity in relation to dust depositional events. Two recently developed complementary techniques (bio-orthogonal noncanonical amino acid tagging and deuterium isotope probing) in combination with Raman Confocal Microspectroscopy will be used to assess and quantify microbial activity in ice. During phase one of the project, these methods will be optimized using deaccessioned ice cores available at the National Science Foundation’s Ice Core Facility. In phase two, ice cores in a time series from the Taylor Glacier will be analyzed for geochemistry and microbial activity. Research results will provide a comprehensive view of englacial microbial communities, including their metabolic diversity and activity, and the effect of geochemical parameters on microbial assemblages from different climate periods. Given the dearth of information available on englacial microbial communities, the results of this research will be of particular significance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.