Review

Water-immiscible dissolved oxygen carriers in combination with Pluronic F 68 in bioreactors

S. K. O. Ntwampe¹*, C. C. Williams² and M. S. Sheldon²

¹Department of Agriculture and Food Science, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town, 8000, South Africa.

²Department of Chemical Engineering, Faculty of Engineering, Cape Peninsula University of Technology, Cape Town, 8000, South Africa.

*Corresponding author. E-mail: Ntwampes@cput.ac.za. Tel: +27 21 460 9097.

Accepted 27 November, 2009

   Abstract

The supply and availability of dissolved oxygen (DO) in aerobic bioprocesses is often a limiting factor for the scaling up, improvement and general performance of these bioprocesses. The use of different DO carriers, particularly the use of perfluorocarbons as oxygen carriers, is discussed in this review. It also highlights interactions of microbial cultures with the surfactant, Pluronic F 68. Although oxygen carriers have been used extensively in the medical field, this review only focuses on their use in microbial bioprocess used for the production of high-value bioproducts. The use of water-immiscible compounds in combination with Pluronic F 68 in bioprocesses is discussed with the intention of analysing their combined effect where bioreactor and biomass performance is affected by DO limitations, nutrient starvation, high concentrations of trace element ions, oxidative stress and cell death from mechanical stress.

Key words: Dissolved oxygen, oxygen carriers, perfluorocarbon, Pluronic F 68, surfactant.