Controlled manipulation and actuation of micro-objects with magnetotactic bacteria

Bacterial actuation and manipulation are demonstrated where Magnetospirillum gryphiswaldense magnetotactic bacteria (MTB) are used to push 3 mu m beads at an average velocity of 7.5 mu m s(-1) along preplanned paths by modifying the torque on a chain of magnetosomes in the bacterium with a directional magnetic field of at least 0.5 G generated from a small programmed electrical current. But measured average thrusts of 0.5 and 4 pN of the flagellar motor of a single Magnetospirillum gryphiswaldense and MC-1 MTB suggest that average velocities greater than 16 and 128 mu m s(-1), respectively could be achieved. (c) 2006 American Institute of Physics.