Screening of freshwater and seawater microalgae strains in fully controlled photobioreactors for biodiesel production

International audienceh i g h l i g h t s A screening procedure was developed to select an optimal strain for biodiesel production. TAG productivity and cell fragility, affecting TAG recovery in wet environment, were considered. 14 seawater and freshwater microalgae strains were screened. Large variation between the strains on numerous screening criteria was found. N. gaditana and P. kessleri were found to be the most promising strains for biodiesel production. a b s t r a c t Strain selection is one of the primary hurdles facing cost-effective microalgal biodiesel production. Indeed, the strain used affects both upstream and downstream biodiesel production processes. This study presents a screening procedure that considers the most significant criteria in microalgal biodiesel production including TAG production and wet extraction and recovery of TAGs. Fourteen freshwater and seawater strains were investigated. Large variation was observed between the strains in all the screening criteria. The overall screening procedure ultimately led to the identification of Parachlorella kessleri UTEX2229 and Nannochloropsis gaditana CCMP527 as the best freshwater and seawater strains, respectively. They featured the largest areal TAG productivity equal to 2.7 Â 10 À3 and 2.3 Â 10 À3 kg m À2 d À1 , respectively. These two strains also displayed encouraging cell fragility in a high pressure bead milling process with 69% and 98% cell disruption at 1750 bar making them remarkable strains for TAG extraction in wet environment