Monitoring Nutrient Limitations by Online Capacitance Measurements in Batch Fed-batch CHO Fermentations

摘要

Capacitance measurements can give valuable information on the physiological state of a culture. Sequential nutrient limitations for batch and fed-batch CHO fermentations were monitored online. The viable, i.e metabolically active, cell density is oneof the most important parameters to monitor in any cell culture process. In development and production it can be useful e.g. for the timing of cell transfers in the inoculum train or from inoculum to production reactors and for the timing of feed additions in fed-batch processes. The online measurement of culture turbidity, fluorescence, or capacitance properties have been used to estimate the biomass concentration (1-5). Currently available and often employed optical density probes have limitations when cell viabilities decrease as they measure culture turbidity rather than viable cell density (2).