Modeling and Validation of Starch, TAGs, and Functional Biomass Kinetics of Green Microalgae as a Function of Nitrogen Concentration

The aim of this study was to elucidate the primary limiting factors affecting the starch and TAGs kinetics of green microalgae, using a modeling approach. The model separately simulated starch, TAGs, functional biomass, chlorophyll, nitrogen quota content, and nitrogen concentration as a function of a number of parameters, which are related to microalgae metabolism. Depending on the factors affecting the accumulation of TAGs from photosynthesis and starch glycolysis, four sets of limiting conditions were considered. The best model for predicting starch and TAGs was selected according to the Akaike Information Criterion (AIC). The set of equations that best fitted the experimental data suggested that the photosynthetic rate and nitrogen quota were the only limiting factors affecting TAGs production. In addition, these equations were able to predict other published experimental results for TAGs. Overall, the proposed mechanism depicts a more complex relationship between starch and TAGs than previously reported for composition models.