Structure-guided mutations of phototropin proteins for optimization of photosynthesis in algae microfactories

Carbon-neutral goods production and energy-efficient agriculture are essential for a sustainable economy.

Microalgae are photosynthetic organisms with high potential as cellular factories for sustainable production of fine chemicals, for waste-water treatment, or for CO2 fixation. However, their industrial use is currently limited. One hurdle is that their photosynthetic activity is capped at about 10-20% at full sun exposure.

This limitation is controlled by phototropin, which is a photoreceptor protein in microalgae and plants. Phototropin should be engineered, to enhance the energy efficiency of microalgae.

We aim accelerating advances towards this goal by solving pioneering structures of phototropin.We propose (1) to solve pioneering structures of phototropin in its resting and photoactivated states by cryo EM; (2) to demonstrate mutations that dampen its photoresponse, and (3) to implement these mutations in C. reinhardtii, as to improve the efficiency of carbon fixation and biomass production of the organisms.

We have already expressed and purified the protein and obtained promising cryo EM data of phototropin.By enabling the use of green algae in industrial processes and providing plant biotechnology with a new handle for optimization of crops, the research is broadly relevant to the United Nations´ Sustainable Development Goals.

The project can make a significant long-term impact on our planet by reducing our dependence on fossil fuels and mitigating climate change.