It’s not only dogs and rats that can sniff out explosives. Genetically modified Escherichia coli bacteria can also do it. At least, that is the belief of the students from TU Delft, Leiden University and Hogeschool Rotterdam who have formed a team to participate in the annual design competition for bacterium, the iGEM (International Genetically Engineered Machine competition) in Boston. The aim of the competition is to modify bacteria such that they can do useful things. The students named their bacterium Ellactrace. The bacterium should light up when it comes into contact with chemicals that seep from old land mines, such as TNT, DNT and DNB.