Raytheon is recruiting glowing microbes to help search for buried explosives. Being developed under a DARPA contract, the company is working with Worcester Polytechnic Institute to use synthetic biology techniques to produce two new strains of bacteria – one to seek out hidden explosives below ground and a second on the surface that glows when they're found.

Landmines are one of the horrific remnants of war, killing up to 20,000 people a year, according to the United Nations. In addition, explosives, in general, are often buried for a variety of reasons resulting in land being polluted with explosive compounds.

Not surprisingly, there has been a great push for over a century to develop better ways of finding mines and explosive materials, which is currently extremely difficult, requiring putting personnel into harm's way or the use of complex and expensive robots.

One idea that's been around for years is to produce genetically-engineered bacteria that can be sprayed over an area to seek out explosives and remotely alert disposal teams of their location.

To make this practical, Raytheon is using synthetic biology, which involves applying engineering principles to modify organisms for a particular purpose, to produce two strains of bacteria. If the first one is in the presence of explosive compounds, it interacts with the second, which produces a glow bright enough to be seen at a distance by remote cameras and drones.

"We already know that some bacteria can be programmed to be very good at detecting explosives, but it's harder underground," says Allison Taggart, principal investigator for the Bio Reporters for Subterranean Surveillance program at Raytheon BBN Technologies. "We're investigating how to transport the reporting bacteria to the required depth underground, and then pushing the luminescence up to the surface so it's easily visible.

"Using biosensors underground could help us save lives as well as detect threats to air quality and the water supply. The modular design of the system we're developing will allow us to swap in different components as needed to detect various kinds of threats and contaminants."

Source: Raytheon