Oil production by the marine microalgae Nannochloropsis sp. F&M-M24 and Tetraselmis suecica F&M-M33

► Under N-starvation Nannochloropsis F&M-M24 can accumulate up to 50% neutral lipids. ► Nannochloropsis F&M-M24 grown in a GWP attains lipid productivities of 6.5gm−2d−1. ► Nutrient starvation does not increase lipid content in Tetraselmis suecica F&M-M33. ► Nutrient starvation increases carbohydrates (>50%) in Tetraselmis suecica F&M-M33. ► Nannochloropsis is suitable for biodiesel. Tetraselmis is suitable for bioethanol. Nannochloropsis sp. F&M-M24 and Tetraselmis suecica F&M-M33 were cultivated outdoors in Green Wall Panels under nutrient deficiency to stimulate oil synthesis. Under nitrogen deprivation, Nannochloropsis attained average biomass and lipid productivities of 9.9 and 6.5gm−2day−1, respectively. Starved Tetraselmis cultures achieved a biomass productivity of about 7.6gm−2day−1 and a lipid productivity of 1.7gm−2day−1. Lipids represented 39.1% and 68.5% of non-starved and starved Nannochloropsis biomass, respectively. Starvation did not increase lipid content in Tetraselmis biomass. Important differences in lipid classes and in fatty acid composition were observed under the different cultivation conditions for both microalgae.