What do you get if you cross brewer’s yeast with a jellyfish and a rat?

Genetically modified organisms aren’t only crops and food but include glowing pets, spider-goats capable of producing spider silk and pigs with spinach genes but what do you get if you cross brewing yeast with a jellyfish with a rat? The answer is a cheap explosive detector and regretfully, not a new party drink that changes colour when cheese is mixed into it.

At the Temple University in Philadelphia, Pennsylvania a molecular biologist called Danny Dhanasekaran has succeeded in creating yeast, with a rat’s sense of smell that are capable of identifying the main ingredient in many explosives, trinitriluene or more commonly known as TNT. Once the yeast has detected TNT it produces a glow by employing its jellyfish abilities.

It is Dhanasekaran’s hope to invent a portable detector much cheaper then the already existing bomb detectors that employ electronic olfactory sensors. With his funding from the Defence Advanced Research Projects Agency in the Pentagon it may not be long before we see these yeast sensors in shopping centres, railway stations or built into a mobile phone sized device carried by policemen.

A rat’s olfactory senses work by allowing different odour molecules to fasten onto a specific protein which sends an electrical signal to the brain. Rats have a very accurate sense of smell as their olfactory senses contain about 500 proteins. The reason brewer’s yeast, Saccharyces cerevisiae was selected as the communications channel was because it uses the same type of protein receptors as rats, to detect pheromones for reproduction.

To alert it’s user that they are in the presence of TNT, a jellyfish gene which encodes a green fluorescent protein only visible under ultraviolet light was inserted, resulting in this jellyfish protein being activated when the specific olfactory pathway for TNT is activated.

Using this practice Dhanasekaran hopes to construct identifiers for other chemical and biological weapons. If Dhanasekaran succeeds in properly engineering the yeast, they will live up to 15 days and exist in a semi-solid film built into magazines which fit into mobile phone sized detectors.

Bibliography

Source One:
Pickrell, J 2006, ‘Instant Expert: GM Organisms’, viewed 24 March 2008, <http://www.newscientist.com/channel/life/gm-food/dn9921>

Source Two: Diesel, E, ‘Mutation Paste Gets Results!’, viewed 25 March 2008, <http://cedros.globat.com/~thebrites.org/News/MutationPasteResults.html>

Source Three:
Marks, P 2007, ‘Genetically modified yeast can sniff out explosives’, viewed 24 March 2008, <http://www.newscientist.com/channel/life/gm-food/mg19426036.000-genetically-modified-yeast--can-sniff-out-explosives.html>

Posted By: Jeffrey Hanson