Article

Simultaneous saccharification and co-fermentation of paper sludge to ethanol by Saccharomyces cerevisiae RWB222—Part I: Kinetic modeling and parameters

  1. Jiayi Zhang1,
  2. Xiongjun Shao1,
  3. Oliver V. Townsend1,
  4. Lee R. Lynd1,2,*

Article first published online: 2 JUL 2009

DOI: 10.1002/bit.22464

Issue

Biotechnology and Bioengineering

Biotechnology and Bioengineering

Volume 104, Issue 5, pages 920–931, 1 December 2009

Additional Information

How to Cite

Zhang, J., Shao, X., Townsend, O. V. and Lynd, L. R. (2009), Simultaneous saccharification and co-fermentation of paper sludge to ethanol by Saccharomyces cerevisiae RWB222—Part I: Kinetic modeling and parameters. Biotechnol. Bioeng., 104: 920–931. doi: 10.1002/bit.22464

Author Information

  1. 1

    Chemical and Biochemical Engineering, Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755

  2. 2

    Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755

*Chemical and Biochemical Engineering, Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755; telephone: 603-646-2231; fax: 603-646-2277.

Publication History

  1. Issue published online: 19 OCT 2009
  2. Article first published online: 2 JUL 2009
  3. Accepted manuscript online: 2 JUL 2009 12:00AM EST
  4. Manuscript Accepted: 30 JUN 2009
  5. Manuscript Revised: 16 MAY 2009
  6. Manuscript Received: 3 FEB 2009

Funded by

  • Mascoma Corporation
  • National Institute of Standards and Technology

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

Get PDF (568K)

Keywords:

  • saccharification and co-fermentation (SSCF);
  • model;
  • paper sludge

Abstract

A kinetic model was developed to predict batch simultaneous saccharification and co-fermentation (SSCF) of paper sludge by the xylose-utilizing yeast Saccharomyces cerevisiae RWB222 and the commercial cellulase preparation Spezyme CP. The model accounts for cellulose and xylan enzymatic hydrolysis and competitive uptake of glucose and xylose. Experimental results show that glucan and xylan enzymatic hydrolysis are highly correlated, and that the low concentrations of xylose encountered during SSCF do not have a significant inhibitory effect on enzymatic hydrolysis. Ethanol is found to not only inhibit the specific growth rate, but also to accelerate cell death. Glucose and xylose uptake rates were found to be competitively inhibitory, but this did not have a large impact during SSCF because the sugar concentrations are low. The model was used to evaluate which constants had the greatest impact on ethanol titer for a fixed substrate loading, enzyme loading, and fermentation time. The cellulose adsorption capacity and cellulose hydrolysis rate constants were found to have the greatest impact among enzymatic hydrolysis related constants, and ethanol yield and maximum ethanol tolerance had the greatest impact among fermentation related constants. Biotechnol. Bioeng. 2009; 104: 920–931. © 2009 Wiley Periodicals, Inc.

Get PDF (568K)