Optimization of ethanol production by Saccharomyces cerevisiae UFPEDA 1238 in simultaneous saccharification and fermentation of delignified sugarcane bagasse

Ethanol production by Saccharomyces cerevisiae UFPEDA1238 was performed in simultaneous saccharification and fermentation of delignified sugarcane bagasse. Temperature (32 °C, 37 °C), agitation (80; 100 rpm), enzymatic load (20 FPU/g cellulose and 10%, v/v β-glucosidase or 10 FPU/g cellulose and 5% β-glucosidase) and composition of culture medium were evaluated. Ethanol concentration, enzymatic convertibility of cellulose and volumetric productivity were higher than 25 g/L, 72% and 0.70 g/L h, respectively, after 30 h, when the culture medium 1 and 20 FPU/g cellulose/10%, v/v β-glucosidase or the culture medium 2 and 10 FPU/g cellulose/5% β-glucosidase were used in SSF at 37 °C and 80 rpm. In the SSF with culture medium 2 (supplemented with ammonium, phosphate, potassium and magnesium), 150 L ethanol/t bagasse was achieved, with minimum enzyme loading (10 FPU/g cellulose and 5%, v/v β-glucosidase) for 8%, w/v of solids, which is often an important requirement to provide cost-efficient second generation ethanol processes.

► Adequate conditions of pre-hydrolysis (temperature, agitation and time) for enzymatic digestibility. ► Temperature and agitation values decreased after inoculation of cell. ► Supplementation of the culture medium with ammonium, phosphate, potassium and magnesium increased ethanol production.