Green Energy from the Desert – Algal Bio-Photo-electrochemical cell systems using Chlorella ohadii, for sustainable energy production

Photosynthesis is the process by which solar energy is converted into chemical energy in the form of complex carbohydrates and ATP. With growing interest in photosynthesis as a potential renewable- energy source, Bio-photo-electrochemical cells (BPEC) were designed and fabricated with the purpose of light energy transformation into electrical power or even hydrogen fuel.

In BPEC systems, one of the factors limiting power outputs and efficiency is the molecular damage caused to the photosynthetic protein machinery due to intense radiation exposure for long time periods (e.g. Photoinhibition). To cope with radiation damage and minimize photoinhibition, certain organisms that dwell in high radiation areas have developed special repair mechanisms (e.g. photoprotection). One such organism is the unicellular green micro-algae Chlorella ohadii, which was isolated from soil-crust beds in the Nitzana desert, Israel. Originating from an arid desert area, C. ohadii is a good candidate for improving our BPEC set-up, having a robust photoprotection mechanism and fast proliferation rate. C. ohadii cells that were gently treated, crude thylakoids, and isolated thylakoids have generated photocurrents in the BPEC system, with ferricyanide as the exogenous electron mediator. The current originates from photosynthesis, as it was inhibited upon addition of DCMU.

In this study, we established and evaluated the power-output and performance of an algal BPEC system with C. ohadii cells or thylakoids, demonstrating its potential for sustainable bio-energy production.