Computers & Chemical Engineering, Vol.100, 139-152, 2017
Dynamic metabolic modeling of lipid accumulation and citric acid production by Yarrowia lipolytica
Yarrowia lipolytica has the capacity to accumulate large amounts of lipids triggered by a depletion of nitrogen in excess of carbon source. However, under similar conditions this yeast also produces citric acid decreasing the lipid conversion yield. Three dynamic metabolic models are presented to describe lipid accumulation and citric acid production by Yarrowia lipolytica. First and second models were respectively based on the Hybrid Cybernetic Modeling (HCM) and the Macroscopic Bioreaction Modeling (MBM) approaches. The third model was a new approach based on the coupling between MBM and fuzzy sets. Simulation results of the three models fitted acceptably the experimental data sets for calibration and validation. However, MBM is time-dependent to consider metabolic shifts, and thus impractical for further applications. HCM and Fuzzy MBM adequately managed and described metabolic shifts presenting highlighting features for control and optimization. HCM and Fuzzy MBM were statistically compared reflecting similar results. (C) 2017 Elsevier Ltd. All rights reserved.