Changes in the cell composition of the marine microalga, Nannochloropsis gaditana, during a light:dark cycle

Nannochloropsis gaditana was grown in semicontinuous culture with a circadian light:dark cycle in a flat-panel photobioreactor. The microalga had a maximal protein content (3 pg cell^–1) after 6 h light and then only storage compounds were accumulated that were consumed during the dark phase. Carbohydrates reached their maximum value after 8 h (0.8 pg cell^–1) and lipids after 12 h light (2.5 pg cell^–1). The results demonstrated that young or adult microalgae might be obtained according to the time of day.