S163: Carbohydrate source optimization for a mammalian production cell culture

As the biotech industry becomes more cost-effective in bio-manufacturing, growing efforts are being spent on media optimization to increase volumetric productivity and reduce costs.  As a part of this effort, the medium formulation used in the production of a legacy recombinant therapeutic protein product was evaluated with regards to different nutrient groups using Design of Experiment (DoE) and statistical analysis.  Among the nutrient groups, two carbohydrate sources have been shown to have a significant impact on protein expression when the concentrations are altered.  Moreover, residual sugar analysis revealed that 66% of the two sugars reside in the harvest fluid under the production perfusion fermentation process, indicating feasibility of reduction.  To systematically study the effect of the two sugars on productivity, a custom DoE was performed using a bench-scale passaging regimen that yields critical metabolic indicators comparable to the production perfusion bioreactors.  The results yielded three fundamental findings: First, similar total amounts of the two sugars were consumed regardless of of total sugar input.  Second, consumption of each sugar was affected by the initial concentrations of the two sugars in the medium, indicating competition in uptake.  Third, the level of productivity increase was higher when consumption of one of the sugars was higher than that of the other.  In conclusion, the DoE provided crucial information on how the concentration of the two sugars could be optimized to maximize productivity while reducing cost.  These new formulations are currently being tested in bioreactor fermentations to confirm feasibility towards implementation in commercial manufacturing.