Some bacterial species possess an astonishing ability: They use Earth's magnetic field to orient themselves. To better understand this mechanism, the team led by Argovia-Professor Martino Poggio from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel took a closer look at the "magnetotactic" bacterium Magnetospirillum gryphiswaldense.

Inside this bacterium is a chain of magnetic nanoparticles known as magnetosomes. These act like a biological compass and allow the bacterium to align with Earth's magnetic field.

In their natural habitat, bodies of water or moist sediments, this compass helps the bacteria to advance in a systematic manner when searching for the optimal living conditions. Without this orientation, their movements would be more random, requiring greater time and energy to locate optimal oxygen levels, for example.

The potential applications of these bacteria are considerable. For instance, they could be used in medicine as magnetically controllable "microrobots" for the targeted delivery of drugs. They could also be applied in wastewater treatment, with bacteria absorbing heavy metals and then being easily removed from the water using a magnet.

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