Kinetic modeling of poly(β-hydroxybutyrate) production and consumption by Paracoccus pantotrophus under dynamic substrate supply

Authors

  • M. A. van Aalst-van Leeuwen,

    1. Delft University of Technology, Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Julianalaan 67, NL-2628 BC Delft, The Netherlands; fax: 31-1-527-82355
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  • M. A. Pot,

    1. Delft University of Technology, Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Julianalaan 67, NL-2628 BC Delft, The Netherlands; fax: 31-1-527-82355
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  • M. C. M. van Loosdrecht,

    Corresponding author
    1. Delft University of Technology, Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Julianalaan 67, NL-2628 BC Delft, The Netherlands; fax: 31-1-527-82355
    • Delft University of Technology, Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Julianalaan 67, NL-2628 BC Delft, The Netherlands; fax: 31-1-527-82355
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  • J. J. Heijnen

    1. Delft University of Technology, Kluyver Laboratory for Biotechnology, Department of Biochemical Engineering, Julianalaan 67, NL-2628 BC Delft, The Netherlands; fax: 31-1-527-82355
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Abstract

The objective of the research was to obtain insights into the behavior of microorganisms under feast/famine conditions as often occur in wastewater treatment processes. The response of microorganisms to such conditions is the accumulation of storage polymers like poly(β-hydroxybutyrate). The research was performed using a pure culture of Paracoccus pantotrophus LMD 94.21. A steady-state C-limited chemostat culture was switched to batch mode and a pulse of acetate was added. As long as external substrate (acetic acid) was present, the organism grew and accumulated poly(β-hydroxybutyrate). After depletion of the external substrate, the stored poly(β-hydroxybutyrate) was used as growth substrate. Poly(β-hydroxybutyrate) accumulation was found to be strongly dependent on the growth rate of the organism before the pulse addition of acetate. Poly(β-hydroxybutyrate) accumulation was correlated to the difference in maximum acetate uptake rate and the acetate required for growth. Based on the interpretation of the experimental results, a metabolically structured model has been set up. This model adequately describes the observed kinetics of the poly(β-hydroxybutyrate) formation and consumption. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng55: 773–782, 1997.

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