Geomicrobiology of Fe-rich sediments of Lake Towuti

作为ICDP钻井活动的一部分，GeoFeLT项目调查了印度尼西亚苏拉威西岛Towuti湖富铁沉积物的地球微生物学和生物地球化学。根据两项初步研究的结果，提出了三个主要假设：1。由于图乌提湖水柱和沉积物中铁和其他金属的丰度很高，它们在生物地球化学循环中起着关键作用。2. 托乌提湖是古细菌的铁质海洋的现代模拟物，可以非常详细地研究这些系统的早期成岩作用。3. 湖泊形成以来的古气候变化不仅记录在沉积学和化学参数中，还记录在当前和现存的微生物群落或它们的DNA中。2015年夏季，钻井成功进行。这是ICDP历史上第一次恢复了用于破坏性微生物和地球化学分析的专用岩心。在广泛的现场采样和处理过程中，瞬态参数立即测量，其他样品根据各自的要求保存。共有5个小组在这个研究领域工作。由GeoFeLT小组成员进行的分析与其他研究小组密切协调，以实现最好的覆盖范围。GeoFeLT项目的博士生通过广泛的分析来验证这些假设，特别是孔隙水化学、放射性示踪剂的周转率测量以及分子和微生物分析。初步数据表明，假设1将被证实，假设2将被否定，因为局部现象对系统的影响太大，无法得出一般性结论，对于假设3，年龄模型和古环境重建将由其他小组提供，目前还没有。一篇论文已经发表，另一篇正在提交中。该申请要求将正在运行的博士项目延长12个月，直到计划的3年项目结束。

The GeoFeLT project investigates the geomicrobiology and biogeochemistry of the iron-rich sediment of Lake Towuti, Sulawesi Island, Indonesia, as part of the ICDP drilling campaign. Based on the results from two pilot studies three major hypotheses were formulated: 1. Due to the high abundance of iron and other metals in the water column and sediment of Lake Towuti they play a key role in biogeochemical cycling. 2. Lake Towuti is a modern analogue to the ferrouginous oceans of the Archaea and allow studying early diagenesis of such systems in great detail. 3. The paleoclimatic changes since the formation of the lake are recorded not just in sedimentological and chemical parameters but in the current and extant microbial community or in their DNA as well.In summer 2015 the drilling was carried out successfully. For the first time in ICDP history a dedicated core for destructive microbiological and geochemical analyses was recovered. During the extensive on-site sampling and processing transient parameters were measured immediately, other samples were preserved according to their respective requirements. A total of 5 groups work in this research area. The analyses that were carried out by the GeoFeLT team members were are closely coordinated with the other research groups in order to achieve the best possible coverage. The PhD student of the GeoFeLT project tests the hypotheses through a wide range of analyses, especially pore water chemistry, turnover rate measurements with radiotracers as well as molecular and microbiological analyses. The preliminary data indicate that hypothesis 1 will be confirmed, hypothesis 2 disproved because local phenomena have too much influence on the system to draw any general conclusions, for hypothesis 3 the age model and the paleoenvironmental reconstruction will be provided by other groups and is not yet available. One paper has been published, another one is in submitted. This application requests a 12-month extension of the running PhD project until the end of the planned 3-year project.