Development and validation of a screening procedure of microalgae for biodiesel production: Application to the genus of marine microalgae Nannochloropsis

• Nannochloropsis strains were screened under nitrogen replete and deplete conditions.
• Screening criteria included biomass and TAG productivities and TAG quality.
• Lipidomic profiling provides a complete view of each specie’s lipidome.
• There was up to 5-fold difference in TAG productivity among the 9 strains screened.
• CCMP527 and CCMP537 were the most promising seawater strains for biodiesel production.

Nannochloropsis has emerged as a promising alga for biodiesel production. However, the genus consists of 6 species and hundreds of strains making strain selection a challenge. Furthermore, oil productivity is instrumental to economic viability of any algal strain for industrial production, which is dependent on growth rate and oil content. In most cases, these two parameters have been studied independently. Thus, the goal of this study is to provide a combined method for evaluating strain performance in specially designed photobioreactors together with an in-depth lipidomic analyses. The nine strains of Nannochloropsis tested showed considerable variations in productivity and lipidomics highlighting the importance of strain selection. Finally, Nannochloropsis gaditana CCMP527 and Nannochloropsis salina CCMP537 emerged as the two most promising strains, with an oil content of 37 and 27 dry wt% after 11-day nitrogen starvation, respectively, resulting in TAG productivity of 13 × 10−3 and 18 × 10−3 kg m−3 d−1, respectively.