Outdoor pilot-scale cultivation and techno economic assessment of a novel omega-3 eicosapentaenoic acid over-producing Nannochloropsis oculata strain

Nannochloropsis oculata is a microalga that produces a significant amount of eicosapentaenoic acid (EPA). Cultivating strains in photobioreactors commercially can be challenging. We cultivated a mutant N. oculata strain, capable of accumulating >40 % EPA more than the wild-type strain at laboratory scale, in an outdoor 300 L pilot-scale photobioreactor, in the U.K. The mutant N. oculata recorded the highest amount of EPA quantity at 129.87 mg/g dry cell weight (DCW) compared to the wild-type strain, which accumulated 75.43 mg/g DCW. A techno-economic assessment (TEA) evaluated the feasibility of the study. Using specific combined cultivation scenarios, the process resulted in a positive net present value (NPV) and return on investment (ROI) at £52,156,484.46 and 607.22 % after 10 years, respectively. The TEA of the improved EPA quantity by M1 N. oculata showed the high processing cost could be overcome by high yields and an optimised operational strategy.