BIOETHANOL PRODUCTION FROM XYLOSE RICH HYDROLYSATE BY IMMOBILIZED RECOMBINANT S. cerevisiae IN FIXED-BED REACTOR

Currently, xylose from biomass hemicellulose is still underused and the fermentation of crude hemicellulose hydrolysates is still a challenge due to the presence of inhibitors. Cell immobilization coupled with fixed-bed reactor could set up process conditions of high productivity and yields. Thus, this work analyzed ethanol production in a fixed-bed reactor loaded with Ca-alginate immobilized recombinant S. cerevisiae using undetoxified sugarcane bagasse hemicellulose hydrolysate (USHH) as substrate. Fermentation was carried out in fixed-bed reactor with 100mL of reaction volume, containing 25g of beads (50 g/L of dry cells) and 25 mL of USHH, at 35oC, pH 5.2. After 4 hours of process, all fermentable sugars were consumed, with low xylitol formation, leading to ethanol yield of 0.39 g/g and productivity of 4.4 g/L.h. This is a promising strategy with potential to implement process operation under repeated batch or continuous mode and achieve 2G ethanol production feasibility.