Future Experiments

We still have three experiments to run before the completion of our project:

• To ensure the proof of concept.
• To show that the concentration of bacteria can be stabilized without any other variable measurable than the fluorescence.
• To test the Voigt Plasmids and show the concentration of KillerRed can be managed.
• To test the device, and show it can run automatically the second experiment.

Second Proof of Concept

This proof of concept is a key of the project : we have to show it is possible to control a population with our genetic network.

Control with the fluorescence

As the device is not able to measure the absorbance of the solution, it is important to test the precision of the model predictive control when its only available measure is the fluorescence. It will be the same experiment than the proof of concept, but the correction on the light intensity shall be calculated with only the fluorescence as guide.

Test of the Voigt Plasmid

Test of the Device

Perspectives

Studying bacterial resistance to oxidative stress

The possibility to independently control the amount of KillerRed expressed in the cells and its phototoxic activity will allow us to obtain cell suspension growing at a precisely defined oxidative stress. Our device indeed allows controlling the ROS production rate in living bacteria. In the frame of our model, this means making the quantity IK/C constant. Assuming that ROS disappear at a rate proportional to the ROS concentration, the ROS concentration per living cell will thus remain constant. Our bio-electronic system can thus be useful to study the influence of ROS on cell growth, and to investigate how different genes and molecule affect bacterial resistance to oxidative stress. Practically, one would first determine the specific parameters of the bacterial suspension as explained before, then the light intensity time profile will be calculated with our model and applied to the bacterial suspension.