Optical trapping of Magnetic Helical Bacteria

We trapped micrometer sized helical, magnetic bacteria with optical tweezers. The linear momentum transfer from light onto the helical structure can make the bacteria magnetospirilla magnetotacticum rotate very quickly. The magnetosomes inside the bacterium are nanometer in size and can in principle be arranged into patterns of nanomagnets with multiple optical traps. We describe our first experiments with this type of bacterium in an optical trap and suggest some applications based on estimations of its magnetic dipole moment.