Enhancement of lipid productivity by adopting multi-stage continuous cultivation strategy in Nannochloropsis gaditana

In the present study, a novel process-based cultivation system was designed to improve lipid productivity of Nannochloropsis gaditana, an oleaginous microalga that has high potential for biofuel production. Specifically, four flat-panel photobioreactors were connected in series, and this system was subjected to continuous chemostat cultivation by feeding fresh medium to the first reactor at dilution rates of 0.028 and 0.056 day (1), which were determined based on Monod kinetics. The results show that the serially connected photobioreactor system achieved 20.0% higher biomass productivity and 46.1% higher fatty acid methyl ester (FAME) productivity than a conventional single photobioreactor with equivalent dilution rate. These results suggest that a process-based approach using serially connected photobioreactors for microalgal cultivation can improve the productivity of lipids that can be used for biofuel production. (C) 2017 Elsevier Ltd. All rights reserved.