Get access
Advertisement

Anaerobic metabolism of propionate by polyphosphate-accumulating organisms in enhanced biological phosphorus removal systems

Authors

  • Adrian Oehmen,

    1. Advanced Wastewater Management Centre (AWMC), The University of Queensland, St. Lucia, Brisbane 4072, Australia; telephone: +61 7 3365 7518; fax: +61 7 3365 4726
    Search for more papers by this author
  • Raymond J. Zeng,

    1. Advanced Wastewater Management Centre (AWMC), The University of Queensland, St. Lucia, Brisbane 4072, Australia; telephone: +61 7 3365 7518; fax: +61 7 3365 4726
    Search for more papers by this author
  • Zhiguo Yuan,

    Corresponding author
    1. Advanced Wastewater Management Centre (AWMC), The University of Queensland, St. Lucia, Brisbane 4072, Australia; telephone: +61 7 3365 7518; fax: +61 7 3365 4726
    • Advanced Wastewater Management Centre (AWMC), The University of Queensland, St. Lucia, Brisbane 4072, Australia; telephone: +61 7 3365 7518; fax: +61 7 3365 4726.
    Search for more papers by this author
  • Jürg Keller

    1. Advanced Wastewater Management Centre (AWMC), The University of Queensland, St. Lucia, Brisbane 4072, Australia; telephone: +61 7 3365 7518; fax: +61 7 3365 4726
    Search for more papers by this author

Abstract

Propionate, a carbon substrate abundant in many prefermenters, has been shown in several previous studies to be a more favorable substrate than acetate for enhanced biological phosphorus removal (EBPR). The anaerobic metabolism of propionate by polyphosphate accumulating organisms (PAOs) is studied in this paper. A metabolic model is proposed to characterize the anaerobic biochemical transformations of propionate uptake by PAOs. The model is demonstrated to predict very well the experimental data from a PAO culture enriched in a laboratory-scale reactor with propionate as the sole carbon source. Quantitative fluorescence in-situ hybridization (FISH) analysis shows that Candidatus Accumulibacter phosphatis, the only identified PAO to date, constitute 63% of the bacterial population in this culture. Unlike the anaerobic metabolism of acetate by PAOs, which induces mainly poly-β-hydroxybutyrate (PHB) production, the major fractions of poly-β-hydroxyalkanoate (PHA) produced with propionate as the carbon source are poly-β-hydroxyvalerate (PHV) and poly-β-hydroxy-2-methylvalerate (PH2MV). PHA formation correlates very well with a selective (or nonrandom) condensation of acetyl-CoA and propionyl-CoA molecules. The maximum specific propionate uptake rate by PAOs found in this study is 0.18 C-mol/C-mol-biomass · h, which is very similar to the maximum specific acetate uptake rate reported in literature. The energy required for transporting 1 carbon-mole of propionate across the PAO cell membrane is also determined to be similar to the transportation of 1 carbon-mole of acetate. Furthermore, the experimental results suggest that PAOs possess a similar preference toward acetate and propionate uptake on a carbon-mole basis. © 2005 Wiley Periodicals, Inc.

Get access to the full text of this article

Ancillary