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

拟议的研究旨在通过结合对相同样品的详细有机地球化学、微生物学和矿物学/岩石学研究的信息，深入了解与热液沉淀物和岩石有关的化学自养生命。重点有三个目标：(1)描述热液沉淀物和蚀变岩石中微生物群落的组成和特定的生物标志物清单；(2)将这些发现与基质的特征(矿物组合、地球化学、孔隙度)联系起来；(3)深入了解岩石伴生生物的新陈代谢及其对降水-蚀变-风化的可能影响。设想通过调查MAR沿线不同热液地区的现场样本和体外培养，开发一份针对不同微生物群组的脂类生物标志物的清单。因此，将建立一种工具，通过脂类生物标记物调查与稳定同位素特征的化合物特异性分析相结合，对热液岩石中的微生物组合进行定性和半定量评估。

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.