(192f) Experimental and Computational Characterization of Mass Transfer in High-Turndown Bioreactors

A systematic investigation into free surface mass transfer and cell growth in high-turndown single-use bioreactors is presented. This report, which combines experimental mass transfer measurements with numerical simulation, deconvolutes the combined effects of headspace mixing and the free surface convective mass transfer on cell growth. Under optimized conditions, mass transfer across the interface alone may be sufficient to satisfy the oxygen demands of the cell culture. Within the context of high-turndown bioreactors, this finding provides a counterpoint to traditional sparge-based bioreactor operational philosophy. Multiple monoclonal antibody-producing cell lines grown using this high turndown approach showed similar viable cell densities to those cells expanded using a traditional cell bag rocker.