Applied Biochemistry and Biotechnology

, Volume 106, Issue 1–3, pp 319–335 | Cite as

Optimization of SO2-catalyzed steam pretreatment of corn fiber for ethanol production

  • Renata Bura
  • Rodney J. Bothast
  • Shawn D. Mansfield
  • John N. Saddler


A batch reactor was employed to steam explode corn fiber at various degrees of severity to evaluate the potential of using this feedstock as part of an enzymatically mediated cellulose-to-ethanol process. Severity was controlled by altering temperature (150–230°C), residence time (1–9 min), and SO2 concentration (0–6% [w/w] dry matter). The effects of varying the different parameters were assessed by response surface modeling. The results indicated that maximum sugar yields (hemicellulose-derived water soluble, and cellulose-derived following enzymatic hydrolysis) were recovered from corn fiber pretreated at 190°C for 5 minutes after exposure to 3% SO2. Sequential SO2-catalyzed steam explosion and enzymatic hydrolysis resulted in a conversion efficiency of 81% of the combined original hemicellulose and cellulose in the corn fiber to monomeric sugars. An additional posthydrolysis step performed on water soluble hemicellulose stream increased the concentration of sugars available for fermentation by 10%, resulting in the high conversion efficiency of 91%. Saccharomyces cerevisiae was able to ferment the resultant corn fiber hydrolysates, perhydrolysate, and liquid fraction from the posthydrolysis steps to 89, 94, and 85% of theoretical ethanol conversion, respectively. It was apparent that all of the parameters investigated during the steam explosion pretreatment had a significant effect on sugar recovery, inhibitory formation, enzymatic conversion efficiency, and fermentation capacity of the yeast.

Index Entries

Corn fiber steam pretreatment enzymatic hydrolysis posthydrolysis fermentation ethanol 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Anderson, R. A. and Watson, S. A. (1982), in Handbook of Processing and Utilization in Agriculture, vol. 2, Wolff, I. A. ed., CRC, Boca Raton, FL, pp. 31–61.Google Scholar
  2. 2.
    Grohmann, K. and Bothast, R. J. (1996), Process Biochem. 32, 405–415.CrossRefGoogle Scholar
  3. 3.
    Moniruzzaman, M., Dale, B. E., Hespell, R. B., and Bothast, R. J. (1997), Appl. Biochem. Biotechnol. 67, 113–126.CrossRefGoogle Scholar
  4. 4.
    Allen, S. G., Schulman D., Lichwa, J., and Antal, M. J. (2001), Ind. Eng. Chem. Res. 40, 2934–2941.CrossRefGoogle Scholar
  5. 5.
    Bura, R., Mansfield S. D., Saddler J. N., and Bothast R. J (2002), Appl. Biochem. Biotechnol. 98–100, 59–72.PubMedCrossRefGoogle Scholar
  6. 6.
    Overend, R. P. and Chornet, E. (1987), Phil. Trans. R. Soc. Lond. 321, 523–536.ADSGoogle Scholar
  7. 7.
    TAPPI, Technical Association of the Pulp and Paper Industry (1998), TAPPI Standard Methods, T-222 om-98, TAPPI Press, Atlanta, GA.Google Scholar
  8. 8.
    Ghose, T. K. (1987), Pure Appl. Chem. 59, 257–268.Google Scholar
  9. 9.
    Box, G. E. P., Hunter, W. G., and Hunter J. S. (1978), in Statistics for Experimenters, John Wiley & Sons, New York, NY, pp. 510–539.MATHGoogle Scholar
  10. 10.
    Clark, T. A. and Mackie, K. L. (1987), J. Wood Chem. Technol. 7, 373–403.Google Scholar
  11. 11.
    Boussaid, A., Jarvis J., Gregg, D. J., and Saddler, J. N. (1997), in The Third Biomass Conference of the Americas, Overend, R. P. and Chornet, E., eds., Montreal, Canada, Elsevier Science, pp.878–880.Google Scholar
  12. 12.
    Stenberg, K., Tengborg, Ch., Galbe, M., and Zacchi, G. (1998), J. Chem. Technol. Biotechnol. 71, 299–308.CrossRefGoogle Scholar
  13. 13.
    San Martin, R., Perez, C., and Briones, R. (1995), Bioresour. Technol. 53, 217–223.CrossRefGoogle Scholar
  14. 14.
    Shevchenko, S. M., Chang, K., Robinson, J., and Saddler, J. N. (2000), Bioresour. Biotechnol. 72, 207–211.CrossRefGoogle Scholar
  15. 15.
    Excoffier, G., Toussaint, B., and Vignon, M. R. (1991), Biotechnol. Bioeng. 38, 1308–1317.CrossRefGoogle Scholar
  16. 16.
    Hespell, R. B., O’Bryan, P. J., Moniruzzaman, M., and Bothast R. J. (1997), Appl. Biochem. Biotechnol. 62, 87–97.Google Scholar
  17. 17.
    Montgomery, R. and Smith, J. (1970), J. Am. Chem. Soc. 79, 695–699.CrossRefGoogle Scholar
  18. 18.
    Delgenes, J. P., Moletta, R., and Navarro J. M. (1996), Enzyme Microb. Technol. 19, 220–225.CrossRefGoogle Scholar
  19. 19.
    Clark, T. A., Mackie, K. L., Dare, P., H. and McDonald, A. G. (1989), J. Wood Chem. Technol. 9, 135–166.Google Scholar
  20. 20.
    Schwald, W., Smaridge, T., Chan, M., Breuil, C., and Saddler, J. N. (1987), in Enzyme Systems for Lignocellulose Degradation, Coughlan, M. P. ed., Elsevier, New York, NY, pp. 231–242.Google Scholar

Copyright information

© Humana Press Inc. 2003

Authors and Affiliations

  • Renata Bura
    • 1
  • Rodney J. Bothast
    • 2
  • Shawn D. Mansfield
    • 1
  • John N. Saddler
    • 1
  1. 1.Forest Products Biotechnology, Department of Wood ScienceUniversity of British ColumbiaVancouverCanada
  2. 2.Fermentation BiochemistryNational Center for Agricultural Utilization Research, USDA, ARSPeoria

Personalised recommendations