Abstract

Continuous ethanol production eliminates much of the unproductive down-time associated with batch process and increases the productivity. Many studies showed that the cell immobilization leads to improve fermentation rates by the high cell concentrations, option of reusability and protection of cells from toxic effects of low pH, temperature, inhibitors, etc. The thermotolerant yeast Kluyveromyces sp. IIPE453 was immobilized on sugarcane bagasse chips and packed in a column. The maximum volumetric productivity 21.87 ± 0.75 g l^-1 h^-1 was achieved with ethanol concentration of 17.5 ± 0.6 g/l and sugar utilization of 76 ± 2.4% at dilution rate of 1.25 h^-1 by feeding 50 g/l glucose concentration. The maximum 18.65 ± 0.75 g l^-1 h^-1 volumetric productivity was achieved with ethanol concentration of 37.3 ± 1.5 g/l and sugar utilization of 54±6.5% at dilution rate of 0.5 h^-1 by feeding 150 g/l glucose concentration.

Key words: Kluyveromyces sp., ethanol fermentation, continuous process, immobilization, sugarcane bagasse chips.