ETHANOL-PRODUCTION AT 45-DEGREES-C USING PREPARATIONS OF KLUYVEROMYCES-MARXIANUS IMB3 IMMOBILIZED IN CALCIUM ALGINATE AND KISSIRIS

The thermotolerant yeast, K. marxianus IMB3, was grown in free and imm obilized states in batch-fed culture at 45 degrees C and ethanol produ ction was examined over a 61-day period. The organism was grown in the free state, in the free state with mineral kissiris, immobilized in c alcium alginate and immobilized in calcium alginate together with kiss iris. Initially, reactors were fed every two days with 10% (w/v) gluco se-containing media and no significant difference in ethanol productio n was observed. In subsequent refeeding experiments, reactors were re- fed every two days with 15% (w/v) sucrose-containing media. Although o verall ethanol concentrations decreased, production in the immobilized systems was higher. In the final stages fermentations were re-fed eve ry 3 days and although overall ethanol production decreased further, p roduction remained highest in the systems containing calcium alginate and kissiris.