Collaborative Research: Biogeochemistry and Geomicrobiology of Taylor Glacier Basal Ice

摘要这项拟议的研究将解决冰冻圈生物学中一个新出现的令人兴奋的问题：微生物是否能够在冰川冰中新陈代谢？拟议的研究将通过现场测量和实验室实验相结合的方式，全面评估泰勒冰川(南极洲麦克默多干谷)基冰的生物地球化学和地质微生物学。我们的整体方法将提供数据，将营养物质的可用性、地球化学成分和气体成分与基础冰序列中的微生物细胞密度、多样性和新陈代谢状态联系起来。对同一冰相进行多样本分析将能够评估基冰中的化学和微生物联系，以及微生物在现场改变气体成分的方式。拟议的方法将解决国家研究委员会的“基因组时代的极地生物学前沿”(2003)概述的两个关键问题：(I)“这种(冰冻的)环境中的微生物能繁殖吗？”和(Ii)“在不同的零下环境中，微生物之间有什么相似之处和不同之处？”确认在-17摄氏度的冰川冰中就地存在微生物活动将代表着冰冻圈生物学的一项重大进展，并显著扩大了生物圈的已知边界。这些信息与冰芯古气候群落高度相关，因为它将为一些冰芯气体记录中的不一致提供一个可行的解释。极地冰川的底部冰带与火星北部冰盖边缘地带的分层沉积物显示出相似之处。因此，我们的研究也将对有关火星上冰中微生物持久性和生存的讨论产生影响。这项研究将支持2名新的研究人员，并为2名博士生和2名本科生提供培训。将积极招聘来自科学和工程领域无代表社区的学生担任这些职位。通过将我们的成果纳入密歇根州立大学正在建设的NSF资助的(DERMEED-1)图书馆，作为国家(SMETE)数字图书馆的一部分，将维护和扩展针对有兴趣从事科学事业的学生的基于网络的工具。

AbstractThe proposed research will address an emerging and exciting question in cryospheric biology: are microorganisms capable of metabolism in glacier ice? The proposed study will involve a comprehensive assessment of the biogeochemistry and geomicrobiology of Taylor Glacier (McMurdo Dry Valleys, Antarctica) basal ice via a combination of field measurements and laboratory experiments. Our holistic approach will provide data to connect nutrient availability, geochemical composition, and gas composition with microbial cell density, diversity and metabolic status in the basal ice sequence. Multi-sample analysis of the same ice facies will allow assessment of the chemical and microbial linkages in basal ice and the manner by which microbes may modify gas compositions in situ. The proposed approach will address two key questions outlined by the National Research Council's "Frontiers in Polar Biology in the Genomic Era" (2003): (i) "Can microorganisms in this (frozen) environment reproduce?" and (ii) "What are the similarities and differences among microorganisms in different subzero environments?" Confirming that microbial activity occurs in situ in glacier ice at temperatures of -17C would represent a significant advance in cryospheric biology and significantly expand the known boundaries of the biosphere. Such information is highly relevant to the ice core paleoclimatic community, as it would provide a viable explanation for inconsistencies in some ice-core gas records. The basal ice zones of polar glaciers show similarities with the layered deposits evident in images of the marginal zones of the northern ice cap on Mars. Thus, our research will also have implications relevant to discussions about microbial persistence and survival in ice on Mars. This research will support 2 new investigators, and provide training for 2 Ph.D. students and 2 undergraduate students. Students from unrepresented communities in science and engineering will be actively recruited for these positions. Web-based tools to target students interested in pursuing a career in science will be maintained and expanded upon by incorporating our results into the NSF funded (DERMEED-1) library under construction at MSU, as part of the national (SMETE) digital library.