A methodology for building a macroscopic FBA-based dynamical simulator of cell cultures through flux variability analysis

• A dynamical FBA-based simulator of hybridoma cell fed-batch cultures is proposed.
• A comparative flux variability analysis is used to deal with system underdetermination.
• The model is successfully validated on experimental data of two fed-batch cultures.
• This study is a contribution in the search for adequate constraints and cost function.
• Results are in agreement with overflow metabolism description available in literature.

A dynamical FBA-based simulator of hybridoma cell fed-batch cultures predicting the dynamics of biomass growth, substrate consumption (glucose and glutamine), metabolites production (lactate, ammonium and alanine) and associate intracellular metabolism based on a simplified metabolic network is proposed. A preliminary comparison between the range of admissible flux distribution obtained based on all available measurements (the two substrates uptake rates and the three metabolite production rates) and based on only part of them (only the two substrates uptake rates) is performed to deal with the usual problem of system underdetermination in constraint-based modeling context. This comparative flux variability analysis allows the objective identification of some additional constraints (to be used in the final FBA-based simulator) so as to obtain similar admissible flux intervals in both cases. Moreover, the proposed approach legitimates the cost criterion used for the linear optimization, i.e. cell growth maximization. This methodology is validated on experimental data of two fed-batch cultures and cross validated on a batch culture of hybridoma cells HB-58. The flux distribution results are in agreement with overflow metabolism description available in literature.