Essencia Coli

Schematic illustration of the setup for controlling concetration of molecule 'X'

The main idea is to synthesize a molecule 'X' and at the same time measure the concentration of this molecule outside the cell in order to keep the concentration constant. This concentration can then be modulated using light intensity. This creates a controll system with feedback from the outside concentration of molecule 'X'.

For proof of concept the molecule 'X' is set to be vanillin, in principle this can be any molecule as long as it can be synthesized and a receptor is available. The light receptor will activate transcription of A on irradiation of blue light which should stimulate synthesis of Vanillin. The concentration vanillin outside the cell is measured with a vanillin receptor this will result in transcription of B. Molecule A will stimulate the synthesis of Vanillin, while molecule B will block the actions of molecule B. This effect is done by a key/lock setup, The translation of the Vanillin synthesizing proteins need a key in order to translate, therefore the synthesize Vanillin will be synthesized and can freely diffuse out of the cell.