Scientists turn bacteria into logic gates

For the past several years, researchers have been creating living logic gates, using the genetic on and off switches we've discovered in the biochemical world to create simple logical functions. But these systems typically run into a wall: we can only stuff so many functions into a single bacterium before the noisy processes with the cell start to interfere with their function, causing unpredictable results. Now, researchers have avoided this problem by getting small populations of bacteria to produce soluble factors that act as circuit wires. Arranged appropriately, these bacteria can perform any possible logical function.