Modeling the effect of CO₂ limitation in continuous fermentation for biosuccinic acid production

The present work investigates a new mathematical formulation for the continuous fermentation production of biosuccinic acid. The model takes into account the effect of CO₂ limitation by the introduction of a specific production rate term that dynamically regulates the formation of the fermentation products. A good model prediction is achieved at different continuous conditions where glucose and sugars-rich industrial waste are utilized as substrates. By model prediction and experimental results, a change in the products ratio is observed when the liquid concentration of CO₂ decreases below 0.18 g/L. A biosuccinic acid titer of 14.94 ± 0.97 g/L was achieved in the continuous process, with a maximum productivity of 1.18 g/L h, and a CO₂ uptake rate of 0.258 ± 0.041 g/Lh. Overall, the presented model demonstrated to be a reliable tool to successfully forecast the fermentation outcomes and explain the CO₂ limitation effects on the product and by-products formation rate. Furthermore, the application of the model to the fermentation process presents a valuable link between the production capacity and the accurate prediction of the CO₂ uptake potential.