Modelling of Ethanol Production from Red Beet Juice by Saccharomyces cerevisiae under Thermal and Acid Stress Conditions
Donaji Jiménez-Islas1, Jesús Páez-Lerma2, Nicolás Oscar Soto-Cruz2 and Jorge Gracida1,3*
1Department of Biotechnology, Polytechnic University of Pachuca, Ex–Hacienda de Santa Bárbara, Carretera Pachuca–Cd. Sahagún Km. 20, Zempoala, 43830 Hidalgo, Mexico
2Department of Chemical and Biochemical Engineering, Technological Institute of Durango, Blvd. Felipe Pescador 1830 Oriente, 34080 Durango, Mexico
3Department of Biotechnology, Autonomous University of Queretaro, Cerro de Las Campanas, 76010 Queretaro, Mexico
Article history:
Received December 5, 2012
Accepted January 16, 2014
Key words:
Beta vulgaris L., modelling parameters, logistic, Pirt and Luedeking-Piret equations
Summary:
In this work the effects of pH and temperature on ethanol production from red beet juice by the strains Saccharomyces cerevisiae ITD00196 and S. cerevisiae ATCC 9763 are studied. Logistic, Pirt, and Luedeking-Piret equations were used to describe quantitatively the microbial growth, substrate consumption, and ethanol production, respectively. The two S.cerevisiae strains used in this study were able to produce ethanol with high yield and volumetric productivity under acid and thermal stress conditions. The equations used to model the fermentation kinetics fit very well with the experimental data, thus establishing that ethanol production was growth-associated under the evaluated conditions. The yeast S. cerevisiae ITD00196 had the best fermentative capacity and could be considered as an interesting option to develop bioprocesses for ethanol production.
*Corresponding author: 
+52 442 192 1200, Ext. 5557
+52 442 192 1200, Ext. 5570