A comparative study of photosynthetic unit models for algal growth rate and fluorescence prediction under light/dark cycles

Accurate description of light-limited algal growth, especially under short light/dark (L/D) cycles, is crucial for prediction of photobioreactor performance and for optimization of operating conditions. Here, a variety of widely used photosynthetic unit (PSU)-based models are evaluated to determine their ability to predict algal specific growth rate and photochemical efficiency under a range of light/dark cycle conditions. Six models were fit to previously published experimental data for algal specific growth rate and photochemical efficiency. Subsequently the weighted sum of squared error (SSE) values, normalized sensitivities to parameter change, and corrected Akaike Information Criterion (AICc) scores were compared. The quality of the fits and the model sensitivities were used to evaluate the assumptions and relative merits of the models considered. For the available data under light/dark cycling conditions, the Bernardi Model scored significantly better on the AICc measure and shows good potential for future use in predicting algal behavior under L/D cycles.