Optimizing semi-continuous cultivation of Arthrospira platensis C1 for phycocyanin production using dynamic modeling

The production of C-phycocyanin (C-PC) from Arthrospira platensis is strongly influenced by nitrogen availability. In the present study, we used our previously developed ODE-based dynamic model to simulate the effects of ammonium concentrations ranging from 0.25 to 2.0 mM N on C-PC and biomass production in A. platensis C1. Comparisons with experimental data demonstrated the model's high predictive accuracy in both batch and semi-continuous systems, supported by low RMSE values and high correlation coefficients. Model-guided optimization of semi-continuous processes revealed that an initial ammonium concentration of 1.8 mM N, with a 36 h harvesting interval, significantly enhanced the C-PC content to approximately 28 % DW. This model offers a robust framework for managing nitrogen levels and optimizing cultivation intervals to maximize C-PC content. These insights underscore the model’s utility as a tool for optimizing C-PC production while promoting sustainable practices in microalgae cultivation.