Fractional factorial study of hybridoma behavior. 2. Kinetics of nutrient uptake and waste production.

A fractional factorial experimental method was used to identify important variables and variable interactions which affect nutrient uptake and waste production. The variables studied include glucose, glutamine, base medium, lactate, and ammonium. Cellular glucose uptake was stimulated by glucose and glutamine and inhibited by lactate. Glucose, base medium, and glutamine all had large stimulative effects on lactate production. Glucose uptake and lactate production both exhibited Monod-type dependencies on the glucose concentration. Ammonium production was sensitive to the glucose and lactate concentrations at levels below about 8 and 20 mM, respectively. Mathematical descriptions of glucose uptake and of lactate and ammonium production were developed. These experimental results have significant implications for the optimization of hybridoma growth in bioreactors.