2024/03/18 by Mathias M. Claus, Marcus Wyss, Claus, Mathias M. +11 · 1 voice
Biochemistry, Genetics and Molecular Biology · Materials Science · #Electromagnetic Fields and Biological Effects #Geomagnetism and Paleomagnetism Studies #Magnetic Properties of Alloys #Magnetic and Electromagnetic Effects
paper · doi:10.1103/lffn-l7m6
openalex created_date 2026/01/09 · openalex publication_date 2026/01/09 · openalex updated_date 2026/02/02
Many bacteria share the fascinating ability to sense Earth's magnetic field-a process known as magnetotaxis. These bacteria synthesize magnetic nanoparticles, called magnetosomes, within their own cell body and arrange them to form a linear magnetic chain. The chain, which behaves like a compass needle, aligns the microorganisms with the geomagnetic field. Here, we measure the magnetic hysteresis of an individual bacterium of the species Magnetospirillum gryphiswaldense via ultrasensitive torque magnetometry. These measurements, in combination with transmission electron microscopy and micromagnetic simulations, reveal the magnetic configurations of the magnetosomes, their progression as a function of applied field, as well as the total remanent magnetic moment and effective magnetic anisotropy of a chain within a single bacterium. Knowledge of these properties is crucial both for understanding the mechanisms behind magnetotaxis and for the design of systems exploiting magnetotactic bacteria in biomedical applications.