Effect of photoperiod regimes on growth, biomass and pigment content of Nannochloropsis sp. BJ17

Nannochloropsis sp. is a green micro alga that has been widely applied for live feed and pigment source for aquaculture animals. The effects of different photo periods of 8:16,12:12,18:6 and 24:0h light:dark regimes on cell growth, biomass concentration, chlorophyll a and carotenoid values of Nannochloropsis sp. BJ17 were examined. The results exhibited that different photoperiods significantly influenced the growth, biomass production, chlorophyll a and carot enoid values of Nannochloropsis sp. BJ17. The highest maximum specific growth rate of 2.04 day^-1, maximum cell concentration of 51 × 10⁶ cells mL^-1 and biomass concentration of 0.842 g L^-1 were produced under 24 h light regimes. The highest chlorophyll a 12.858 μg mL^-1 and carot enoidof 5.138 μg mL^-1 were registered under continuous illumination. We conclude that cell growth, biomass and chlorophyll a and carotenoid content of Nannochloropsis sp. BJ17 were significantly affected by photoperiod.