Biogeomagnetism is about the interactions of organisms with the geomagnetic field. Nikolai Petersen has established this research in Munich in the early 1980ies, when discovering magnetic bacteria in deep-sea sediments. Since about 1995 we got into the biophysical mechanisms of magnetic-field reception in higher organisms. The research topics investigated are truly interdisciplinary and so we have begun to collaborate with internationally recognised experts in the fields of microbiology, biophysics and neurophysiology.
More specifically, we are concerned with the following topics:
Photo: Marianne Hanzlik
Discovered in 1975, these microorganisms can be found in most aquatic
habitats and are characterized by intracellularly synthesized
ferrimagnetic crystals, so-called magnetosomes (grain-size about 50
nm). The crystals, usually consisting of magnetite, are arranged in the
form of one or several chains. Such a magnetosome chain can be thought
of as a microscopic compass needle, which makes the bacterium swim
along magnetic field lines. At present, we investigate magnetic
properties of magnetosomes and look into the long standing problem of
magnetite biomineralization in magnetic bacteria (in cooperation with
Dirk Schüler at the MPI for Marine Microbiology in Bremen).
Besides, we try to find out if the magnetite crystals found in Martian meteorites are of bacterial origin (cooperation with Imre Friedmann, NASA Space Science Division, California).
Probably the most spectacular project (in collaboration with Henrique Lins de Barros and Darci Motta at the CBPF in Rio de Janeiro and Marcos Farina at UFRJ) focuses on a multicellular procaryote, an organism consisting of roughly twenty identical cells each of which contains a chain of magnetosomes. Here we try to answer the question if this evolutionary peculiarity is a dead end or an in-between stage. Our first results indicate that the organisms are at least magnetically optimized.
Migratory birds and other migrating animals can use the Earth's magnetic field for orientation in their long-distance travels. The biophysical mechanism underlying this remarkable treat are however not known thus far. We managed to identify a structural candidate for the magnetic-field receptor in the beak of homing pigeons and at the moment try to magnetically characterize the magnetic material which forms the core of the magnetoreceptor (in collaboration with Uwe Hartmann, Saarbrücken). We have started to apply the same methodology to zebra fish and trout to localize a magnetic-field receptor in fish (with Denis Scherbakov, Uni Stuttgart Hohenheim).
Since 1995 we have been collaborating with Valera Shcherbakov (Russ. Academy of Science) on theoretical biophysical models of magnetic-field reception.