Thermodynamic electron equivalents model for bacterial yield prediction: Modifications and comparative evaluations
Article first published online: 6 NOV 2006
Copyright © 2006 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 97, Issue 2, pages 377–388, 1 June 2007
How to Cite
McCarty, P. L. (2007), Thermodynamic electron equivalents model for bacterial yield prediction: Modifications and comparative evaluations. Biotechnol. Bioeng., 97: 377–388. doi: 10.1002/bit.21250
- Issue published online: 23 APR 2007
- Article first published online: 6 NOV 2006
- Manuscript Accepted: 11 OCT 2006
- Manuscript Received: 2 MAR 2006
- bacterial yields;
- C1 compounds
Modifications are made to an earlier thermodynamic model (TEEM1) for prediction of maximum microbial yields from aerobic and anaerobic as well as heterotrophic and autotrophic growth. The revised model (TEEM2) corrects for lower yields found with aerobic oxidations of organic compounds where an oxygenase is involved and with growth on single-carbon (C1) compounds. TEEM1 and TEEM2 are based on energy release and consumption as determined from the reduction potential or Gibbs free energy of ½-reaction reduction equations together with losses of energy during energy transfer. Energy transfer efficiency is a key parameter needed to make predictions with TEEM2, and was determined through evaluations with extensive data sets on aerobic heterotrophic yield available in the literature. For compounds following normal catabolic pathways, the best-fit value for energy transfer efficiency was 0.37, which permitted accurate predictions of growth with a precision of 15%–20% as determined by standard deviation. Using the same energy transfer efficiency, a similar precision, but somewhat less accuracy was found for organic compounds where oxidation involves an oxygenase (estimates 8% too high) and for C1 compounds (estimates 17% too high). In spite of the somewhat lower accuracy, the TEEM2 modifications resulted in improved predictions over TEEM1 and the comparison models. Biotechnol. Bioeng. 2007;97: 377–388. © 2006 Wiley Periodicals, Inc.