Researchers have been able to create bacteria that can reproduce color photographs by adding new genetic pathways into the organisms. The scientists have managed to engineer the bacteria so that they can sense different colors of light, and then replicate it by creating the corresponding colored pigments.
The team from the Massachusetts Institute of Technology (MIT) originally started experimenting with using Escherichia coli bacteria to produce images over a decade ago. Back then, however, they were limited to creating black and white images. Now, they have managed to tweak the engineering with such precision that they can create synthetic pathways that can even register color.
The bacteria art has a much wider purpose than just looking pretty impressive, it is actually the result of some quite complex synthetic biology that could have multiple applications from industry to medicine. The researchers have effectively customized the bacteria by tinkering with a set of 18 genes that are required to sense the light and then translate that into pigment, publishing their work in Nature Chemical Biology.
The individual bacteria contain genes that respond only to either red, blue, or green light. This information is sensed, before being sent through a circuit that processes the information, before sending it down a series of pathways until the bacteria can produce a pigment that matches the color of the initial light input. This allowed the researchers to shine color images onto the plate of bacteria, and then watch as the organisms replicated it.
Using light to produce and control biological processes is becoming quite a common technique. Optogenetics describes using light to control cells in living tissue, and is frequently used on neurons to manipulate their activity. This latest study, however, could have uses in other contexts. It could be modified, for example, so that rather than producing a simple pigment, the cells can produce a specific drug, enzyme, or chemical that can then be harvested.
What the team has managed to produce is of a much higher resolution than anything achieved before. But it’s not quite as straightforward as it may look. The images took multiple attempts to get right, but when they managed it, can last for a surprisingly long time. One of the researchers has recounted how he has had one image on the wall of his office for years.
In the future, scientists may attempt to refine the images even further, by adding in more circuits and sensors that will be able to “see” and then produce intermediary pigments.