Kinetic exploration of intracellular nitrate storage in marine microalgae

Abstract

ABSTRACTIn this study, a recently developed model accounting for intracellular nitrate storage kinetics was thoroughly studied to understand and compare the storage capacity of Phaeodactylum tricornutum and Amphora coffeaeformis. In the first stage the identifiability of the biokinetic parameters was examined. Next, the kinetic model was calibrated for both microalgal species based on experimental observations during batch growth experiments. Two kinetic parameters were calibrated, namely the maximum specific growth rate and the nitrate storage rate (). A significant difference was observed for the nitrate storage rate between both species. For P. tricornutum, the nitrate storage rate was much higher ( = 0.036 m3 g−1 DW d−1) compared to A. coffeaeformis ( = 0.0004 m3 g−1 DW d−1). This suggests that P. tricornutum has a more efficient nitrate uptake ability and intracellular nitrate storage capacity and also indicates the need for determination of in order to quantify nitrate storage.