A Kinetic Model for Simultaneous Saccharification and Fermentation of Avicel With Saccharomyces cerevisiae
Article first published online: 30 NOV 2010
Copyright © 2010 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 108, Issue 4, pages 924–933, April 2011
How to Cite
van Zyl, J. M., van Rensburg, E., van Zyl, W. H., Harms, T. M. and Lynd, L. R. (2011), A Kinetic Model for Simultaneous Saccharification and Fermentation of Avicel With Saccharomyces cerevisiae. Biotechnol. Bioeng., 108: 924–933. doi: 10.1002/bit.23000
- Issue published online: 16 FEB 2011
- Article first published online: 30 NOV 2010
- Accepted manuscript online: 12 NOV 2010 12:00AM EST
- Manuscript Accepted: 25 OCT 2010
- Manuscript Revised: 17 OCT 2010
- Manuscript Received: 13 JUL 2010
- numerical model;
This work describes a numerical model for predicting simultaneous saccharification and fermentation of Avicel, an insoluble crystalline cellulose polymer. Separate anoxic cultivations of 40 g/L glucose and 100 g/L Avicel were conducted to verify model predictions and obtain parameters to describe the reaction kinetics. Saccharification of Avicel was achieved with Trichoderma reesei cellulases from the enzyme preparation Spezyme CP with an enzyme loading of 10 FPU/g cellulose. Cultivations were supplemented with 50 IU/g cellulose of β-glucosidase from Novozym 188 to prevent product inhibition by cellobiose. Saccharomyces cerevisiae MH-1000 is a robust industrial strain and was used to ferment glucose to ethanol, glycerol, and carbon dioxide. The numerical model presented in this paper differs from previous models by separating the endoglucanase and exoglucanase enzyme kinetics and allowing for inhibitive site competition. Assuming all enzymes remain active and that each enzyme complex has a corresponding constant specific activity, the model is capable of predicting adsorbed enzyme concentrations with reasonable accuracy. Comparison of predicted values to experimental measurements indicated that the numerical model was capable of capturing the significant elements involved with cellulose conversion to ethanol. Biotechnol. Bioeng. 2011; 108:924–933. © 2010 Wiley Periodicals, Inc.