Device

We have designed a “Carbon Stress Buster” device that rescues E.coli cells from substrate depletion conditions, and/or situations where the glycolytic pathway (the metabolic pathway that converts glucose to usable energy) is inhibited. Our device has the following subparts:

• Green-light absorbing Proteorhodopsin (GPR) generator.
• Carbon stress induced promoter upstream of the PR generator.
• A system for providing the Chromophore “Retinal” for light absorption activity of GPR.

The device is induced by carbon stress in terms of decrease in substrate concentration in the media, and GPR is generated. Proteorhodopsin with retinal is expressed on the bacterial membrane. When green light of wavelength 525 nm is shone on the bacterial culture, Proteorhodopsin’s proton pumping activity is initiated, and the PMF (Proton Motive Force) increases. Through ATP synthase which is constitutively expressed on the bacterial membrane, the PMF drives ATP synthesis and rescues the cells in substrate stress conditions.

We propose using this device for a variety of applications including enhancing recombinant protein yield for low substrate conditions (Project Artemis) and for light-based screening for positive clones (Project Sunscreen).