ETHANOL-PRODUCTION FROM CELLULOSE AT 45-DEGREES-C USING A HATCH-FED SYSTEM CONTAINING ALGINATE-IMMOBILIZED KLUYVEROMYCES-MARXIANUS IMB3

The thermotolerant yeast, Kluyveromyces marxianus IMB3, was grown in b atch culture at 45 degrees C on cellulose-containing media, supplement ed with exogenous cellulase activity. At various stages during ferment ation, both substrate and enzyme were added in batch mode and fermenta tion was continued for 220 h. Ethanol production increased to 20 g/l a t 200 h, representing 45% of the maximum theoretical yield. In subsequ ent experiments, the organism was immobilized in calcium alginate bead s and these were used in a similar, batch-fed system at 45 degrees C. Again, fermentation was continued for 220 h and ethanol production inc reased to its maximum, of 28 g/l, within 100 h and this represented in excess of 60% of the maximum theoretical yield.