REPEATED BATCH 2G ETHANOL PRODUCTION FROM SUGARCANE BAGASSE HEMICELLULOSE HYDROLYSATE BY IMMOBILIZED RECOMBINANT S. cerevisiae STRAIN

Ethanol production from undetoxified hydrolysates is a challenge for the feasibility of biofuel production processes due to the presence of inhibitors. The use of xylose assimilating recombinant yeasts, associated with cell immobilization advantages, could set up process conditions for high productivity and yield. This work analyzed repeated batch 2G ethanol production from undetoxified sugarcane bagasse hemicellulose hydrolysate by Ca-alginate immobilized recombinant S. cerevisiae with and without beads washing between batches. For this purpose, fermentations were carried out at 35oC, pH 5.2 and 4g of beads for 4mL of urea supplemented hydrolysate. The inclusion of a washing step was not effective in improving cell viability. However, fermentation results were promising: in both experiments encapsulated yeast performed three batches with ethanol yields close to the theoretical (0.48 g/g) and high productivity (2.5 g/L/h).