US scientists create living computer out of bacteria

Researchers have programmed a virulent microbe, the E. coli, to potentially solve complicated mathematics problems. The researchers have found that computing in living cells is feasible, opening the door to a number of applications. The second-generation bacterial computers illustrate the feasibility of extending the approach to other computationally challenging maths problems. A research team from Missouri Western State University and Davidson College in North Carolina engineered the DNA of E. coli. They were able to create bacterial computers capable of solving a classic mathematical problem known as the Hamiltonian Path Problem. The Hamiltonian Path Problem asks whether there is a route in a network from a beginning node to an end node, visiting each node exactly once. The researchers modified the genetic circuitry of the bacteria to enable them to find a Hamiltonian path in a three-node graph. Bacteria that successfully solved the problem reported their success by fluorescing both red and green, resulting in yellow colonies.