To understand the role of magnetotactic bacteria and how they contribute to the paleomagnetic and environmental signature of sediments

大多数淡水和海洋环境中存在广泛的趋磁细菌和其他含有纳米级铁矿物的磁性微生物。这些物种被认为在铁循环中发挥重要作用。它们对沉积物剩磁的贡献直到现在才在古地磁学界得到重视，但人们对它们如何或为什么利用地球磁场将自己置于其存在的特定生态位中知之甚少。在我们位于Niederlippach的古地磁实验室范围内的一个池塘中生活着高细菌种群密度和广泛多样的磁性微生物，慕尼黑大学（LMU）已同意建立Niederlippach生物磁学中心，初始投资为227 k€，等待DFG的额外支持。我们的目标是利用这个池塘作为研究磁性细菌的天然实验室，特别关注了解它们的生活习惯以及它们在控制沉积物中如何获得剩磁方面的作用。据我们所知，该中心将与LMU的Dirk Schüler微生物学小组共同运营，这将是世界上第一个此类中心。（1）三维地球化学剖面（Eh、pH、S ~ 2等）;（2）相同剖面中细菌的磁性特征，（3）导致磁化强度和随后的磁信号变化的成岩过程，（4）使用化石趋磁细菌作为地质历史中的环境代用指标。

Most freshwater and marine environments host a broad spectrum of magnetotactic bacteria and other magnetic microorganisms that contain nano-sized iron minerals. These species are thought to play an important role in the iron cycle. Their contribution to the magnetic remanence of sediments is only now gaining appreciation in the paleomagnetic community, yet little is known how or why they use the Earth s magnetic field to place themselves in the particular ecological niche in which they exist. A high bacterial population density and broad diversity of magnetic microorganisms live in a pond within the confines of our paleomagnetic laboratory in Niederlippach, where the University of Munich (LMU) has agreed to establish the Niederlippach Center of Biomagnetism, with an initial investment of 227 k€ pending additional support from the DFG. Our goal is to use this pond as a natural laboratory to study magnetic bacteria, with particular focus on understanding their living habits and their role in governing how a magnetic remanence is acquired in sediments. To our knowledge, this Center, run together with the microbiology group of Dirk Schüler at LMU, will be the first of its kind in the world. Our proposed research concerns: (1) three-dimensional geochemical profiling (Eh, pH, S2~, etc.) of the pond, (2) magnetic characterization of the bacteria in the same profiles, (3) diagenetic processes leading to the acquisition of magnetization and subsequent changes in the magnetic signal, and (4) use of fossil magnetotactic bacteria as environmental proxies in the geological past.