Microbial Oceanography of ChemolithoAutotrophic planktonic Communities

模拟模型预测，由于海洋表面沃茨分层增加和温度上升，全球海洋的含氧量将减少25%，直到世纪结束。这种氧气的损失将不可避免地导致全球海洋中缺氧和缺氧区域的扩大，对海洋碳和氮循环产生重大影响。在这个建议中，我们评估的功能多样性chemolithoautotrophic原核生物群落在两个对比鲜明的海洋环境中，深水质量的北大西洋沿着纬度梯度和周围的氧化还原跃层在波罗的海中部。这两种环境已被证明以前港口高度活跃chemolithoautotrophic原核生物群落与暗二氧化碳固定率接近地表水浮游植物的活动。具体的重点是把在这两个系统中的碳和氮循环，包括在波罗的海中部的硫循环的原核生物的功能多样性。生物地球化学速率测量与使用宏基因组学和元转录组学等方法进行的功能基因分析密切相关。从这些分析中获得的信息将指导进一步深入研究这两个系统水柱中的地球化学相关过程。孵育实验使用稳定和放射性同位素结合分子技术，如SIP-RNA分析，单细胞分析，使用拉曼荧光原位杂交，NanoSIMS和MICRO-FISH将允许洞察的功能多样性的化学无机营养微生物群落的动力学在缺氧和缺氧的海洋微生物系统。实地研究将由实验室模型系统与孤立的关键球员补充，以了解适应能力和性能的化能无机自养生物在不同的环境条件。这些方法的结合将为我们理解黑暗海洋中的浮游化能无机自养提供基础。

Simulation models predict that the oxygen content of the global ocean will decrease by 25% until the end of the century due to an increased stratification of the oceanic surface waters and a rise in temperature. This loss in oxygen will inevitably lead to an expansion of hypoxic and anoxic areas in the global ocean with major consequences for the oceanic carbon and nitrogen cycling. In this proposal, we assess the functional diversity of chemolithoautotrophic prokaryotic communities in two contrasting marine environments, the deep-water masses of the North Atlantic along a latitudinal gradient and around the redoxcline in the central Baltic Sea. Both environments have been shown previously to harbor highly active chemolithoautotrophic prokaryotic communities with dark carbon dioxide fixation rates approaching surface water phytoplankton activity. Specific focus is put on the functional diversity of prokaryotes in the carbon and nitrogen cycling in both systems, including the sulfur cycle in the central Baltic. Biogeochemical rate measurements are tightly linked to functional gene analyses using among other approaches metagenomics and metatranscriptomics. Information obtained from these analyses will guide further in-depth studies of geochemically relevant processes in the water column of the two systems. Incubation experiments using stable and radio-isotopes in combination with molecular techniques such as SIP-RNA analyses, single-cell analyses using Raman-FISH, NanoSIMS and MICRO-FISH will allow insights into the dynamics of the functional diversity of chemolithotrophic microbial communities in suboxic and anoxic marine planktonic systems. Field studies will be complemented by laboratory model systems with isolated key players in order to understand the adaptive capacity and performance of chemolithoautotrophs in response to different environmental conditions. The combination of these approaches will provide the base for a significant advancement in our understanding of planktonic chemolithoautotrophy in the dark ocean.