Evaluation of the alcoholic fermentation kinetics of enzymatic hydrolysates from sugarcane bagasse (Saccharum officinarum L.)
Correspondence to: R. R. Andrade, Faculdade de Engenharia Química Universidade Estadual de Campinas (UNICAMP) Caixa Postal 6066, 13083-970 Campinas São Paulo, Brazil. E-mail: firstname.lastname@example.org
The efficient production of bioethanol by Saccharomyces cerevisiae using lignocellulosic biomass as raw material depends on the fermentability of the hydrolysates. In this work the evaluation of the kinetics of ethanol production by S. cerevisiae using enzymatic hydrolysates was performed and compared with the kinetics of diluted sugarcane molasses fermentation.
A term for inhibition by acetic acid was added to a previous model, the kinetic parameters were re-estimated and the model has been shown to describe accurately new experiments with distinct hydrolysates proportions as fermentative media. Among all the kinetic parameters, a great reduction in μmax (from 0.437 to 0.37 h−1, at 34°C), and increment in Ypx (from 9.89 to 16.63 kg kg−1, at 34°C) were noted, which strongly affected the kinetics of fermentation.
The kinetic parameters obtained for hydrolysates differed very significantly from those obtained using molasses, which shows that models developed to describe the kinetics of first generation ethanol production need to be reformulated and adapted to describe the kinetics of second generation ethanol fermentation. The productivities achieved were between 1 and 3 kg m-3 h−1, which are considered acceptable for alcoholic fermentations in batch mode, showing the good fermentability of hydrolysates even without detoxification. © 2012 Society of Chemical Industry