Facultad de Ciencias Químicas
IB. Karla Daniela González Gloria
Abstract: Bioethanol is an alternative used as a biofuel, i.e., to replace fossil fuels such as petroleum gasoline; it is used as a renewable source of energy; second-generation of bioethanol is produced from lignocellulosic materials, such as wheat straw. For the fermentation stage, the yeast Saccharomyces cerevisiae is used, which is a microorganism that plays an essential role in the industrial bioethanol production; it has several advantages due to its high ethanol productivity, as well as its high tolerance to glucose concentrations and inhibitors in lignocellulosic hydrolysates. The present project is based on the study of the Saccharomyces cerevisiae yeast with two types of strains, a flocculant (CA11) and a non-flocculant (PE-2), where the growth of both strains was evaluated at different temperatures from 30 to 45ºC and to different substrate concentrations (glucose) of 50, 100 and 150 g/L in terms of evaluating the performance in screening culture tubes and flask scale, selecting the best conditions for the fermentation stage with the pre-simultaneous saccharification and fermentation (PSSF) operative strategy. The PE-2 strain was selected where the temperature of 40ºC and the concentration of 100 g/L of glucose were chosen, obtaining an ethanol production of 68.19 g/L in a time of 72h.