The potential productivity of the microalga, Nannochloropsis oceanica SCS-1981, in a solar powered outdoor open pond as an aquaculture feed

The microalga, Nannochloropsis, is receiving increased attention for their potential application as a biodiesel feedstock and an aquaculture feed. Nannochloropsis cultured in different environments has been shown to possess different growth characteristics and the biochemical composition. The biochemical composition are critical as they dictate applicability and profitably of the species. In the present study, the outdoor productivity of Nannochloropsis oceanica SCS-1981 was investigated in a novel open pond that was completely powered by solar-electricity. Using this technique, the maximum cell density in the solar-powered open pond was 1.1 × 108 cell mL−1, with proteins the dominant biochemical component (53.1% of dry weight). Additionally, the microalga accumulated a high content of eicosapntemacnioc acid (EPA) comprising nearly 3% of the dry weight. Probiotics, such as Phaeodactylibacter, were present in the culture pond, which was a gram-negative bacteria that has been reported to have a positive effect on the absorption and immune system of cultured animal. The results of the study indicated that N. oceanica was suitable for aquiculture feeds. The productivity of biomass was 5.8 g m−2 d−1, which was similar to traditional raceway ponds. Considering that the solar-powered open pond requires no additional energy input, the costs of culturing can be significantly reduced. This culturing method is easy to work with and would be an easy technique to be used in the culturing of Nannochloropsis as living aquaculture feeds. The study will greatly promote the low-cost cultivation of microalgae for aquaculture feed purposes.