Aug. 31, 2020

​BGU researchers have managed to improve the photosynthetic efficiency of single cell algae by an order of magnitude at the light intensities of average-to-peak sunlight. Single-cell algae are nature's smallest photosynthetic machines. They exploit visible light for generating biomass at efficiencies well above that of higher plants. Still, conventional large-scale algal bioreactors, which operate in sunlight, only exploit a small fraction of the solar energy. For decades, many university and industrial labs worldwide have struggled to increase this low bioreactor efficiency.

"The laboratory-scale proof-of-concept presented in this novel research offers an extraordinary opportunity in the fields of solar fuels and algal biotechnology. Translating to large-scale commercial solar-driven algae cultivation plants constitutes a future challenge that will require skillful optical, mechanical and hydrodynamic engineering," say co-authors of the study Emeritus Professors Yair Zarmi and Jeffrey Gordon of BGU's Alexandre Yersin Department of Solar Energy & Environmental Physics (YDSEEP) at the Jacob Blaustein Institutes for Desert Research (BIDR) . In collaboration with colleagues at the Algae Biofuel Division of India's giant industrial company, Reliance Industries Ltd, they published their findings in iScience (Cell Press). The proof-of-concept opens the door to unprecedented yields in the production of biofuels and pharmaceuticals.
"The key was demonstrating how the judicious use of pulsed light leads to a marked boost in the photosynthetic efficiency of algae by synchronizing biological time scales (of the order of several milliseconds) and photonic timescales," say Professors Zarmi and Gordon.

The journal paper provides extensive reproducible experimental evidence, complemented by a biophysical model that explains the observations and provides guidelines for improvement (e.g., by genetic engineering). ​