Chlorella sp. strain:SLA-04 Genome sequencing

For algal biofuels to replace fossil fuels, it is imperative that cultivation systems are not constrained by proximate availability of flue gas or other high concentration CO2 sources and the energy and infrastructure burden to deliver CO2 over long distances. We propose cultivation of microalgae in high salinity and alkalinity media to achieve high biomass productivity and culture stability. As alkaliphilic cultures grow, HCO3- is taken up by the algae, CO2 is abstracted and fixed while OH- is released. In parallel, due to the high pH of the medium, gaseous CO2 is dissolving into the culture medium at a rapid rate even from ambient air. The resulting high alkalinity in the growth medium ensures that sufficient HCO3- remains available in solution for continued carbon fixation. At night, when photosynthesis is absent, the bicarbonate depleted from solution during the day is replenished via transfer of CO2 from the atmosphere. Our strategy is to use this high pH and high alkalinity culturing strategy to achieve high productivity cultivation of Chlorella sorokiniana strain SLA-04 without any inputs of concentrated CO2. Additional productivity improvements are envisioned through the development of molecular toolkits including metabolic modeling combined with targeted genome editing.