Biosignatures in precipitates and altered rocks at hydrothermal systems of the Mid-Atlantic Ridge: organic geochemistry, microbiology and petrography

该研究旨在通过结合对相同样品进行详细的有机地球化学、微生物学和矿物学/岩石学调查的信息，深入了解与热液沉淀物和岩石相关的化学岩石自养生命。主要有三个目标：(1)描述热液沉淀物和蚀变岩石中存在的微生物群落的组成和特定生物标志物清单；(2)将这些发现与基质特征（矿物组合、地球化学、孔隙度）联系起来；(3)深入了解岩石伴生物的代谢及其对降水-蚀变-风化的可能影响。设想通过对沿着MAR和体外培养的各种热液区域的现场样品的调查，开发具有不同微生物群特征的脂质生物标志物清单。因此，将建立一种工具，通过脂质生物标志物研究结合稳定同位素特征的化合物特异性分析，对热液岩石中的微生物关联进行定性和半定量估计。

The proposed study aims to gain insight into the chemolithoautotrophic life associated to hydrothermal precipitates and rocks by combining the information from detailed organicgeochemical, microbiological, and mineralogical/petrographical investigations on identical samples. Three goals are in focus (i) to describe the composition and specific biomarker inventory of the microbial community present in hydrothermal precipitates and altered rocks (ii) to relate these findings to the characteristics of the substrate (mineral assemblage, geochemistry, porosity) (iii) to obtain insight into the metabolism of rock associates and their possible effect on precipitation - alteration - weathering. It is envisaged to develop an inventory of lipid biomarkers characteristic for the distinct groups of microbiota by investigation of field samples from a variety of hydrothermal areas along the MAR and in vitro cultures. Thus, a tool is to be established allowing for a qualitative and semi-quantitative estimation of microbial associations in hydrothermal rocks by lipid biomarker investigation combined with compound specific analysis of stable isotope signatures.