Postprint version. Published in Supramolecular Science, Volume 5, Issue 3-4, January 1, 1998, pages 383-390. Copyright © 1998 Elsevier. The definitive version is available at http://dx.doi.org/10.1016/S0968-5677(98)00036-4.
Magnetotactic bacteria orient and migrate along magnetic field lines. This ability is based on a submicron assembly of single-magnetic domain iron mineral particles that elegantly solves the problem of how to construct a magnetic dipole that is large enough to be oriented in the geomagnetic field at ambient temperature, yet fit inside a micron-sized cell. The solution is based on the ability of the bacteria to accumulate high concentrations of iron, and control the deposition, size and orientation of a specific iron mineral at specific locations in the cell.