Team:Paris Saclay/Project


Revision as of 01:55, 18 October 2014 by Maschi (Talk | contribs)



IGEM teams use live organism systems to perform specific functions, as mechanics build a machine. Working with life still raises a lot of ethical questions like the representation of life and our team has chosen Bio-Art to explore this subject. To illustrate these questions, we chose an object "made-in-nature", a lemon, and we tried to make an equivalent "made-in-IGEM". This object has the same external properties of a lemon: smell, form and a colour that slowly changes from green to yellow, like a lemon when it ripens. Moreover we use Fastlemon to raise ethicals issues.


In a collaboration with iGEM Paris-Bettencourt team in our iGEM French Meeting, we made a video to introduce the project.


Scientific part

Our project is based on the construction of a bacterial lemon that will look like lemon but made only of Escherichia coli modified to produce a lemon scent and to change colour from green to yellow. We will achieve our project by genetically modifying Escherichia coli to be devoid of any unpleasant odour by deleting the genes involved in E. coli's odor, by introducing genes for the production of the lemon scent and finally by adding a yellow-blue chromoprotein whose expression is controlled by a tRNA suppressor for the colour switching.

Remove the bad smell of E. coli

Our lemon should smell like a lemon. Our chassis is Escherichia coli , a bacterium known to have a foul odor. We thus have to remove the genes involved in this particular phenotype. The tnaA gene is required for the degradation of tryptophan into indole, the main molecule at the origin of E. coli smell. We use a phage transduction method to reach our goal.

Lemon Scent

The particular odor of lemon is mainly due to 3 monoterpenes: limonene, beta-pinene and geranial. We will clone the 3 monoterpene synthases responsible for the production of these 3 molecules into our bacteria to allow them to produce this fragrance. We will also improve the production of the GPP precursor using a synthetic mevalonate pathway using the construction of the team of T. S. Lee.

Lemon appearance and Ripening

Since vision is one of the most important senses in humans, we want the lemon to look as real as possible. To achieve this, we plan to make our lemon look green or yellow, like a real one. Furthermore, we also want to simulate the ripening process of the lemon by changing its color gradually from green to yellow.

Artistic Part

Lemon Shaping

1st idea

We basically wanted to build up a lemon tree in which one we would have put lemons we had made. As lemons pass from green to yellow, we would have simulated the season’s cycle.

Boston Installation

2nd idea

The idea was to project the shadow of a little sculpture in a screen or a wall: the positioning of the light with respect to the sculpture would have enabled the creation of shadow ten times bigger than the sculpture itself. The aim of this structure would have been to show the gap between a object and its image, between real things and decoys.

3rd idea (chosen for Boston)

Finally we decided to modify the second idea (for logistic reasons). The element which could this time reveal the gap between an object and its image, between real things and decoys, would be a mirror …