Optimización de las condiciones de fermentación para la producción de etanol de melaza de caña por Kluyveromyces marxianus CCEBI 2011

Abstract

Ethyl alcohol, due to its diverse uses, mainly as alternative fuel, has aimed numerous researches in the last
years, with the purpose to improve the economic efficiency of its production. An alternative, which has been evaluated is
related with the search for thermotolerant and ethanol-resistant yeasts, with abilities to overcome the limitations observed
in traditionally used strains of Saccharomyces cerevisiae specie. The present study was undertaken to find the optimal
fermentation conditions for the ethanol production from sugarcane molasses with the thermotolerant and pectolytic
yeast Kluyveromyces marxianus CCEBI 2011, by using the Response Surface Methodology. A Central Composite Rotable
Design was used for the optimization of three factors: hydrogen ion concentration (pH), temperature and total reducing
sugars concentration. The experimental data was fitted into a second order polynomial regression model with an R2 of
0,931. Temperature and reducing sugar concentration were the statistically significant factors (p < 0,05) on the ethanol
production process. Estimated optimal conditions from regression equation were as follow: pH 4,55, temperature 35,2 oC
and total reducing sugar concentration 105 g/L . The average values experimentally obtained for volumetric productivity,
ethanol concentration and fermentation efficiency were 0,8 g/Lh, 53,1 g/L y 95,1 %, respectively, which are in agreement
with industrial production exigencies.