In October, I wrote that researchers at the University of Rome had coaxed E. coli into pushing the teeth of a tiny crankshaft. Now researchers at the U.S. Department of Energy's Argonne National Laboratory and Northwestern University appear to have accomplished a similar feat using Bacillus subtilis:
A few hundred bacteria work together in order to turn the gear. When multiple gears are placed in the solution with the spokes connected as in a clock, the bacteria will turn both gears in opposite directions, causing the gears to rotate in synchrony - even for long stretches of time.
. . .The speed at which the gears turn can also be controlled through the manipulation of oxygen in the suspended liquid. The bacteria need oxygen in order to swim, and by decreasing the amount of oxygen available, researchers can slow down the gears' movement. Eliminating the oxygen halts the movement entirely.
Once the oxygen is reintroduced into the system, the bacteria “wake up” and begin swimming once again.
In all, very cool stuff.
Previously: "Using E. Coli as an engine"
