Magnetism in living magnetically-induced bacteria

Artificial magnetically-induced bacteria were prepared by labelling probiotic bacteria Lactobacillus fermentum with maghemite nanoparticles. Most bacteria remained alive after magnetic labelling and exhibited good viability. We have used this unique living magnetic material to address an issue never posed before: how does the magnetism of a living magnetic system vary while life proliferates. Monitoring of magnetic properties of this living system confirmed a magnetic dilution during proliferation. During bacteria division, the number of magnetic nanoparticles was equally shared among the daughter bacteria. Chain-like assemblies fixed into a LR-white resin with the application of a magnetic field enhance the anisotropic magnetic properties of this system.