title: Models for high cell density bioreactors must consider biomass volume fraction: Cell recycle example.
abstract: Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity.
authors.affiliation: Chemical Engineering Department, North Carolina State University, Raleigh, North Carolina 27695-7905.
authors.forename: H G
authors.initials: HG
authors.lastname: Monbouquette