Oxygen transfer enhancement in aqueous/perfluorocarbon fermentation systems: I. experimental observations

A new fiber-optic dissolved oxygen sensing technique was applied to the study of two-phase aqueous/perfluorocarbon (pfc) dispersions. These dispersions were examined for their oxygen transfer enhancement capability in the absence and presence of an oxygen-consuming reaction. For the pfc-in-water dispersions, oxygen uptake rate (OUR) enhancements were equal both with and without oxygen-consuming cells present in the aqueous phase. In contrast, for water-in-pfc dispersions, OUR enhancements inthe presence of reaction were limited by oxygen diffusion across the aqueous phase droplets. Nevertheless, enhancement factors of 5-10 on an aqueous phase volume basis were obtained in a 75% pfc dispersion.These oxygen transfer enhancements were directly translatable into enhancements in overall fermenter productivity for actual microbial cultivation systems.