Novel hollow fiber immobilization techniques for whole cells and advanced bioreactors

A novel microporous hollow fiber membrane-based immobilization technique for whole cells has been developed. Yeast cells (Saccharomyces cerevisiae) were grown on chopped hydrophobic microporous hollow fibers as well as on hydrophilic hollow fibers. This immobilization support was used to carry out fermentation in a tubular bioreactor. Air was passed from time to time to facilitate cell growth. The microbial culture reached a very high cell density level of around 10¹⁰/mL of fiber lumen volume. An ethanol concentration of 45 g/L and productivity of 41 g/L-h were obtained with an initial glucose concentration of 100 g/L. The present technique does not have the shortcomings of conventional immobilization methods.