Genomic Explorations into the Microbial Metabolisms of an Active Rift System

尽管科学界和工业界对地球地下生物圈及其与地质过程的相互作用越来越感兴趣，但在很大程度上仍未加以探索。最近对地质活跃的埃格裂谷地区地下的调查提供了对微生物群落结构的深入了解，表明独特的地下条件，包括高CO2浓度，低pH值，地震活动和高温驱动微生物种群动态。罕见的地球化学条件也被认为提供了一个有利于加速和独特的微生物过程和相互作用的环境，使这种系统中的地下微生物生命的“热点”。然而，目前关于陆地地下微生物种群的代谢能力和基因组活性的数据很少，因此需要进行额外的调查。拟议研究的目标是在以前工作的基础上，继续DFG项目LI 3509/1-1下开始的研究，并扩大目前对埃格裂谷微生物过程的理解，地质活动断层区，其特征是频繁的CO2脱气和富含矿物质的流体，通过多组学方法研究代谢潜力和活性基因表达。初步测试有助于开发可行的DNA提取方法，支持最初提出的研究的可行性，并允许使用现代的、基于下一代测序的方法来研究来自埃格裂谷中的切布盆地的新钻探的岩心和富含CO2的水样，这些样品正在由ICDP钻探项目回收（钻探埃格裂谷：活跃大陆裂谷中的地壳，地幔和深层生物圈过程）。最先进的基因组分析将用于识别活跃的微生物群落，恢复（新的）微生物基因组，重建推定的和活跃的代谢网络，并评估地球化学和微生物生态学数据之间的相互作用。第一个宏基因组数据的收集表明，地下岩心样品的特征在于适应独特地下环境的嗜酸、硫氧化和产甲烷微生物群落。这项研究的结果将为地震和流体活跃断层线地区地下微生物生命提供开创性的见解，并为未来的ICDP钻井项目提供有价值的数据。

Despite growing scientific and industrial interest, the terrestrial subsurface biosphere and its interactions with geological processes remain largely unexplored. Recent investigations into the subsurface of the geologically active Eger Rift region provided insights into the microbial community structure, suggesting the unique subsurface conditions, consisting of high CO2 concentrations, low pH, seismic activity, and high temperatures drive microbial population dynamics. The rare geochemical conditions are also assumed to provide an environment favorable for accelerated and unique microbial processes and interactions, making the subsurface in such systems a “hotspot” for microbial life. However, very little data on the metabolic capabilities and genomic activity of terrestrial subsurface microbial populations is currently available, necessitating the need for additional investigations.The goal of the proposed study is to build on the previous work, continue the research started under DFG project LI3509/1-1, and expand the current understanding of microbial processes in the Eger Rift, a unique, geologically active fault region, characterized by frequent CO2 degassing and mineral rich fluids, by investigating the metabolic potential and active gene expression through a multi-omic approach. Initial tests have aided in the development of a feasible DNA extraction method, supporting the feasibility of the initially proposed study, and permitting the use of modern, next generation sequencing based methods to investigate newly drilled core and CO2 rich water samples from the Cheb Basin in the Eger Rift, which are being recovered by the ICDP drilling project (Drilling the Eger Rift: Crust, mantle, and deep biosphere processes in an active continental rift) as of August 2019. State of the art genomic analyses will be used to identify active microbial communities, recover (novel) microbial genomes, reconstruct putative and active metabolic networks, and evaluate interactions between geochemistry and microbial ecology data. Collection of the first metagenomic data demonstrated subsurface drill core samples to be characterized by an acidophilic, sulfur oxidizing, and methanogenic microbial community adapted to the unique subsurface settings. The results from this study will provide groundbreaking insights on microbial life in the subsurface in seismically and fluid-active fault line regions and provide valuable data for future ICDP drilling projects.