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Geochemical-dependent stratification of microbial chemolithoautotrophy in a high carbon dioxide subsurface aquifer

高二氧化碳地下含水层中微生物化能自养的地球化学依赖性分层

基本信息

批准号：
275250470
负责人：
Professor Dr. Alexander Probst
金额：
--
依托单位：
Department of Earth and Planetary Science
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/275250470?language=en
关键词：
Geochemical dependent stratification microbial chemolithoautotrophy

项目摘要

Recent research has detected a vast diversity of novel organisms in aquifers and suggested an unexpected role for carbon dioxide fixation in the deep carbon cycle. The fraction of organisms with the capacity for chemolithoautotrophy (carbon dioxide fixation using inorganic electron donors and acceptors) and the variation of carbon dioxide fixation pathways and activity levels with geochemical environment remain essentially unknown. I propose to explore these questions by analyzing microbial communities in aquifer fluids that are sourced from different depths and geological formations by eruption of Crystal Geyser (Utah, USA) over the four-day eruption cycle. Given the geological context, it is likely that the ~800 m-deep aquifer is stratified, both geochemically and in microbial community composition. I hypothesize that the extent of chemolithoautotrophy, the pathways by which carbon dioxide fixation occurs, and activity levels will vary with availability of oxygen (for near-surface fluids), dissolved ferrous iron, hydrogen, methane, hydrogen sulfide, organic carbon and carbon dioxide concentrations (which varies by at least 30 times over the eruption cycle). I will use genome-resolved metagenomic and metatranscriptomic methods, in combination with geochemical measurements, to evaluate the metabolic potential of community members as a function of fluid composition. For organisms that use identifiable electron donors and acceptors and that are predicted to be autotrophs based on metagenomic analysis, I will use an isotopically labeled carbon dioxide microcosm experiment to test for chemolithoautotrophy. The project will provide new information about the prominence of carbon dioxide fixation in the subsurface and insight into the variety and distribution of chemolithoautotrophic activity as a function of geochemical conditions.

最近的研究在含水层中发现了多种多样的新生物，并提出了在深层碳循环中二氧化碳固定的意想不到的作用。具有化学化石自养能力（利用无机电子供体和受体固定二氧化碳）的生物比例以及二氧化碳固定途径和活性水平随地球化学环境的变化基本上仍然未知。我建议通过分析水晶间歇泉（美国犹他州）在四天喷发周期中来自不同深度和地质构造的含水层流体中的微生物群落来探索这些问题。考虑到地质环境，在地球化学和微生物群落组成方面，~800 m深的含水层很可能是分层的。我假设，化学岩石自养的程度、二氧化碳固定发生的途径和活动水平将随着氧气（近地表流体）、溶解的亚铁、氢、甲烷、硫化氢、有机碳和二氧化碳浓度（在喷发周期内至少变化30倍）的可用性而变化。我将使用基因组解析元基因组学和元转录组学方法，结合地球化学测量，评估社区成员的代谢潜力作为流体成分的函数。对于使用可识别的电子供体和受体并根据宏基因组分析被预测为自养生物的生物体，我将使用同位素标记的二氧化碳微观实验来测试化学岩石自养。该项目将提供关于二氧化碳在地下固定作用的新信息，并深入了解化学岩石自养活动的多样性和分布，作为地球化学条件的函数。