title: Adaptive control at low glucose concentration of HEK-293 cell serum-free cultures.
abstract: Fed-batch cultures were implemented to study the metabolism of HEK-293 cells. Glucose, measured every 30 min by a FIA biosensor system, was maintained at 1 mM throughout the culture using an adaptive nonlinear controller based on minimal process modeling. The controller performed satisfactorily at both low and high cell concentrations without the need for retuning between different culture phases. Overall, lactate production was significantly reduced by maintaining a low glucose concentration, thus decreasing the rate of glycolysis. The rates of glucose and glutamine uptake as well as the lactate and ammonia production were compared to those obtained in batch mode with an initial glucose concentration of 21 mM. Basically, three phases were observed in both culture modes. The metabolic shift from the first to the second phase was characterized by a significant reduction in glucose consumption and lactate production while maximum growth rate was maintained. The specific respiration rate appeared unchanged during the first two phases, suggesting that no change occurred in the oxidative pathway capacity. In the third phase, cell growth became slower very likely due to glutamine limitation.
authors.affiliation: Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montréal, Québec, Canada, H4P 2R2, Département de génie chimique, Ecole Polytechnique, Université de Montréal, Case Postale 6079, Succursale centr.
authors.forename: P
authors.initials: P
authors.lastname: Siegwart
authors.forename: J
authors.initials: J
authors.lastname: Côté
authors.forename: K
authors.initials: K
authors.lastname: Male
authors.forename: J H
authors.initials: JH
authors.lastname: Luong
authors.forename: M
authors.initials: M
authors.lastname: Perrier
authors.forename: A
authors.initials: A
authors.lastname: Kamen
mesh_terms: D000641:Ammonia / Q000378:metabolism; D019149:Bioreactors; D002452:Cell Count; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D002460:Cell Line; D016895:Culture Media, Serum-Free; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D005973:Glutamine / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D019344:Lactic Acid / Q000096:biosynthesis
chemical_list: D016895:Culture Media, Serum-Free; D005973:Glutamine; D019344:Lactic Acid; D000641:Ammonia; D005947:Glucose