Team:Paris Saclay/Project


Revision as of 03:03, 18 October 2014 by MelaCriq (Talk | contribs)



In the beginning of our reflection to choose a project, we had a lot of ideas in wealth, water treatment, and anti-fouling but for each we always raised the same issue: Can we do whatever with genetically modified organisms? These recurring issues get us to think about deeper ethical questions. In effect, synthetic biologists modify living organisms in order to perform specific functions like a machine as the iGEM name illustrate it. But we wonder if these modified organisms are really machines. So our main interrogation was to know how synthetic biology blurs the limits of living beings or if synthetic biology can change our definition of natural/artificial life. Would everybody have the same limit or criteria to define if a life is artificial are not? It would definitely depend on the perception that people will have of this unconventional form of life. To rise all our issues, we choose an artistic approach and in particular a Bio-Art approach. As art is accessible to everybody, we believe that this is the best way to reach the general public and allow them to introspect. Our piece will play with the perception of thing by recreating a living lemon tree. We use synthetic biology to design a lemon , a bacterial lemon, but that will look like a real one: same smell, same shape and color, and that will slowly changes from green to yellow, like a lemon when it ripens. Would you see that our lemon is a (lemon) fake one ? But is it a fake one or another kind of lemon ? that what bring us back to our first question on the definition of the living. An aspect that we have developed in our Ethics part.

As we use the living to make art, it raised a lot of other questions: can we modify and/or use living organisms to create a piece of art work? In fact, everytime that we debate on this question, inside the team or with other iGEMers, scientists or artists, we always arrived at the same critical questions: what is our definition of the living? Do we accept to use everykind of living to do bio-art. Using bacteria is it the same that using rabbit or human body? And finally the use of Bio-Art nourished our ethical questioning. Art, Science and Ethics are so intrigously imbriquée.

La nourriture occupe une part importante dans notre vie et est chargée de symbolique. Avec notre citron, nous souhaitons également faire réagir le public sur nos futures habitudes alimentaires. La nourriture synthétique est –elle l’avenir ? Est-ce que ce citron envahira demain vos frigos ? FastLemon


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 …