Autotrophic and mixotrophic biomass production of the acidophilic Galdieria sulphuraria ACUF 64

Abstract Galdieria sulphuraria is an acidophilic microalga isolated in proximity of sulfuric ponds where pH below 3 and most organisms cannot grow. We cultivated G. ACUF 64 free contamination for over 2 months a medium containing organic carbon at 1.7 with continuous, high intensity, lighting. compared biomass productivity chemostat repeated batch cultivations. The optimal density autotrophic mixotrophic cultures was identified. In autotrophy 28.3 g x ·m −2 ·day −1 , 1.8 to 7.7-fold higher than previously reported. Autotrophy ‘oxygen balanced’ mixotrophy intracellular recirculation O CO take place. Aeration not needed 92% the substrate converted into biomass. times culture linear growth maintained concentration (9.7 ·L ). Light tolerance dense make our strain promising outdoor cultivation. • Highest (29 g·m ) (51 Oxygen balanced does need aeration can be light intensity. (340