Effect of Nitrogen, Phosphorous, and Light Colimitation on Amphidinol Production and Growth in the Marine Dinoflagellate Microalga .

The marine dinoflagellate microalga is a source of amphidinols, a fascinating group of polyketide metabolites potentially useful in drug design. However, grows slowly and produces these toxins in tiny amounts, representing a hurdle for large-scale production. Understanding dinoflagellate growth kinetics under different photobioreactor conditions is imperative for promoting the successful implementation of a full-scale integrated bioproduct production system. This study evaluates the feasibility of growing under different ranges of nitrogen concentration (NO = 882-2646 µM), phosphorus concentration (PO = 181-529 µM), and light intensity (Y = 286-573 µE m s) to produce amphidinols. A mathematical colimitation kinetic model based on the "cell quota" concept is developed to predict both algal growth and nutrient drawdown, assuming that all three variables (nitrogen, phosphorous and light) can simultaneously colimit microalgal growth. The model was applied to the semicontinuous culture of the marine microalgae in an indoor LED-lit raceway photobioreactor. The results show that both growth and amphidinol production strongly depend on nutrient concentrations and light intensity. Nonetheless, it was possible to increase growth while simultaneously promoting the overproduction of amphidinols. The proposed model adequately describes growth, nitrate and phosphate concentrations, and intracellular nitrogen and phosphorus storage, and has therefore the potential to be extended to other systems used in dinoflagellate cultivation and the production of bioproducts obtained therein.