CONTINUOUS PRODUCTION OF ETHANOL USING YEAST-CELLS IMMOBILIZED IN PREFORMED CELLULOSE BEADS

Saccharomyces cerevisiae cells were immobilized on preformed cellulose beads by adsorption. The fermentation capacity of the immobilized yea st cells was found to be practically independent of the hydrogen ion c oncentration between pH 3.1 and 6.25. The fermentation capacity was ma ximal at 30 degrees C. The immobilized yeast cells were used for conti nuous production of ethanol in a fluidized-bead reactor. The average v alues characteristic for the process were an ethanol concentration of 41.9 +/- 0.1 g l(-1), a fermentation efficiency of 82.9 +/- 2.1% and a volumetric productivity of 3.94 +/- 0.52 gl(-1) h(-1).