杏吧原创

A living motor made by combining different parts from bacteria is one of the smallest ever built, and could one day power tiny robots.

Many types of bacteria are propelled by natural motors that power the rotation of tail-like flagella. These rotary pumps, known as stators, are among the world鈥檚 oldest and smallest wheels, being thought to have evolved billions of years ago.

Every bacteria species with this kind of pump follows the same 5:2 design of five small components built around two protein compounds in the middle that act like an axle. This is why at the University of New South Wales, Australia, and his colleagues decided to use gene editing to combine parts of motors from two different species of bacteria, Escherichia coli and Vibrio alginolyticus.

The team tried 14 different combinations of parts before finding one that worked. The resulting 鈥渃himeric microbe motor鈥� is a mere 6 nanometres in diameter and generates electricity to drive its microscopic wheels using sodium in a solution of salt water. 鈥淓ssentially, we have hacked into the bacteria鈥檚 engine,鈥� says Baker.

While other researchers have built smaller, molecule-scale motors, Baker says his team鈥檚 is the first to be powered independently, in a step towards a 鈥渂acteria-based chimera robot鈥�.

鈥淲e are engineering a nano-scale motor that can go where we want and when we want,鈥� he says. 鈥淭he next step is to have that hacked motor carry some cargo, so we can deliver that cargo on demand.鈥�

at Texas A&M University compares the result to swapping the spark plugs in a car with those of a lawnmower and finding they still work. 鈥淭hat suggests the motors of the car and lawnmower motor were based on design principles embodied in an original internal combustion engine that was modified to perform different functions,鈥� he says. 鈥淭his work provides the first experimental evidence that corroborates the hypothesis that all 5:2 electric motors diverged from an ancient common ancestor to perform very different functions in bacteria.鈥�