Microbiological and geochemical studies along the new Greenland NEEM core: from authenticity to microbial diversity and activity

这项研究将使用示踪方法来跟踪冰芯钻探和岩心后松弛过程中外源微生物污染的来源和程度，以确定本土微生物多样性及其与过去气候和一氧化二氮记录的关系。该项目将在北埃米安(？印支线)钻探期间进行。格陵兰岛的深冰芯。具体的目标和方法包括：(1)利用以下方法测试来自不同来源的微生物污染的可能来源：(1)对钻井液进行微生物和分子分析，通过质谱仪跟踪其对冰层的渗透，并通过在特定运行期间在钻孔中提供荧光微球(作为微生物替代品)，以及通过荧光显微镜和流式细胞仪分析覆盖的微球冰芯的薄片，来测试潜在污染物的渗透；(2)使用高分辨率显微镜和流式细胞仪技术来确定不同深度的本地微生物种群的丰度、活性和多样性与沉积气候的关系；(3)将35,000至45,000年前冰中一氧化二氮的元素和同位素组成的可能异常与特定生物体的微生物就地生产联系起来。

"This award is funded under the American Recovery and Reinvestment Act of 2009(Public Law 111-5)."This study will use tracer methodologies to track the origin and extent of exogenous microbial contamination during ice-core drilling and post-core relaxation in order to ascertain the indigenous microbial diversity and its relationship to past climates and to nitrous oxide records. The project would be conducted during the drilling of the North Eemian (?NEEM?) deep ice core in Greenland. Specific objectives and methods include: (1) Testing the possible origin of microbial contamination from different sources using the following approaches: microbiological and molecular analyses of the drilling fluid, tracking its penetration into the ice by mass spectrometry, and testing the infiltration of potential contaminants by delivering fluorescent microspheres (acting as microbial surrogates) in the borehole during particular runs and analyzing thin sections of the microsphere coated ice cores by fluorescent microscopy and flow cytometry; (2) Using high resolution microscopic and flow cytometric techniques to determine the abundance, viability and diversity of the indigenous microbial populations from different depths in relationship to deposition climate; (3) Linking possible anomalies of the elemental and isotopic composition of nitrous oxide in ice dated between 35,000 and 45,000 years to microbial in-situ production by specific organisms.