Outdoor pilot production of Nannochloropsis gaditana: Influence of culture parameters and lipid production rates in raceway ponds

In the present work, a study on the performance, culture parameters and modeling of the growth and lipid productivity of Nannochloropsis gaditana in outdoor pilot-scale raceway ponds is made. During the experiments, modifications to the dilution rate and nutrient supply were performed, with maximum productivities of 0.19 gBIOMASS/l day and 30.4 mgLIPIDS/l day obtained at 0.30-0.36 1/day and 10.5 mM NO3−. The impact of average irradiance within the culture (in the range of 280-350 μE/m2 s) and the specific nitrate input (SNI, below 0.4 mmol N/g day) was correlated with an enhancement of saturated and monounsaturated fatty acid contents, which attained maximum values of 29.5% and 33.0% of total FAs, respectively. The modeling of growth, lipid and fatty acid production rates was developed taking into account the irradiance, dilution rate and SNI, which might prove useful in the scaling-up of raceway ponds with this species.