Team:Paris Saclay/Project

The different parts of our project:

A - The chassis coli Odor free

Escherichia coli stinks because of the tnaA gene which produces an enzyme that transforms the L-tryptophan into indole, responsible for the stench. If we want our lemon to smell like one, we have to delete this gene.

In the lab, we already had a strain in which the tnaA was replaced by a kanamycin resistance, but this strain was too modified to be used for our project. So we switched the tnaA sequence with the kanamycin resistance in our bacterium by phage transduction. After the recombination, we used a flipase to delete the kanamycin resistance. The remaining bacterium doesn't smell at all.

B - Construction of the fusion protein (color)

C - Salicylate Inducible Suppressing System

D - Lemon scent

The aim is to make three different populations of E.coli.

1. The first is tranformed with a plasmid that contains the limonene synthase gene
2. The second is transformed with a plasmid that contains the β-pinene synthase gene
3. The third is tranformed with a plasmid that contains the geraniol synthase gene and the CAD gene to increase citral A and B production by the bacteria

We could thus play with the density of these populations for a better lemon scent, like cooking, putting the right quantity of each ingredient.

E - Banana scent

F - The lemon shaping