Life in Ice: Probing Microbial Englacial Activity through Time

冰川冰芯充当了一个回到过去的博物馆，提供了过去气候条件的详细记录。除了按时间顺序记录温度、化学成分和气体成分外，冰还提供了一个独特的环境，可以随着时间的推移保存微生物和其他生物材料。这些微生物提供了对在地球冰冻圈和其他结冰的行星体中生存所需的生理能力的宝贵洞察，但人们对它们知之甚少。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、工程和医学研究院报告《NSF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。这项工作的更广泛影响是，它将与古气候和生物领域的研究人员相关。它将支持两名早期职业研究人员，一名毕业生和一名本科生，他们将进行实验室分析，参加外联活动，在科学期刊上发表论文，并在会议上发言。这项工作将使用以前收集的冰芯来调查从南极洲泰勒冰川蓝色冰区到最后一次冰盛期的全新世至末次冰盛期的冰盖微生物活动。该提案确定对以下方面作出重大贡献：1)研究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有关的气体和微量元素信息的保存；3)确定岩心中的微生物及其与尘埃沉积事件有关的活动。最近开发的两种互补技术(生物正交非规范氨基酸标记和氚同位素探测)将与拉曼共聚焦显微光谱技术相结合，用于评估和量化冰中微生物的活动。在该项目的第一阶段，这些方法将使用国家科学基金会的冰芯设施中提供的去接入的冰芯进行优化。在第二阶段，将对泰勒冰川时间序列中的冰芯进行地球化学和微生物活动分析。研究结果将全面了解全球微生物群落，包括它们的代谢多样性和活性，以及不同气候时期的地球化学参数对微生物组合的影响。由于缺乏有关微生物群落的现有信息，这项研究的结果将具有特别重要的意义。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.