MONITORING THE PHYSIOLOGICAL STATE OF MAMMALIAN CELL PERFUSION PROCESSES BY ON-LINE ESTIMATION OF INTRACELLULAR FLUXES

Rapid assessment of the cells physiological state during a culture is essential for bioprocess optimization and the design of effective control strategies. In this work, an approach was developed to provide an online estimation of the intracellular flux distribution of cells grown in perfusion cultures, based on a comprehensive metabolic network involving 40 biochemical reactions and 46 components. The specific uptake and production rates were evaluated from daily nutrient and metabolite concentration measurements, using an extended Kalman-filter for noise reduction and rate estimation. The biosynthetic rates were determined from an on-line estimate of the specific growth rate using a recursive least-squares method. Our results demonstrate that this approach allows monitoring of the cells metabolic activity and can be a useful tool for process development.