Team:Paris Saclay/Project




In the beginning of our reflection to choose a project, we had a lot of ideas in health, 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 illustrated in the word "iGEM." 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 or 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 things 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 change from green to yellow, like a lemon when it ripens. Would you consider our lemon as a fake? Another kind of lemon? This brings us back to our first question on the definition of life, an aspect that we have developed in our Ethics part.

As we use living beings 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, every time that we debate on this question, within 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 every kind of living to do Bio-Art? Is using bacteria the same that as rabbits or humans? And finally the use of Bio-Art nourished our ethical questioning. Art, Science and Ethics are so intricately intertwined.

Food is essential to our lives and is filled with symbolism. With our lemon, we wish that the public will think about future food consumption habits. Is synthetic food the future? Will this lemon be found in your fridge one day?


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


The question of living-being's representation reminded us Magritte's work. But our inspirations came from others artistic works. Indeed, the idea of our project is fully referenced. In this section we described how these artists and their concepts help us to build and design our 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 …