Archives of Microbiology

, Volume 139, Issue 4, pp 351–354

Aerobic denitrification: a controversy revived

  • Lesley A. Robertson
  • J. Gijs Kuenen
Original Papers

DOI: 10.1007/BF00408378

Cite this article as:
Robertson, L.A. & Kuenen, J.G. Arch. Microbiol. (1984) 139: 351. doi:10.1007/BF00408378


During studies on the denitrifying mixotroph, Thiosphaera pantotropha, it has been found that this organism is capable of simultaneously utilizing nitrate and oxygen as terminal electron acceptors in respiration. This phenomenon, termed aerobic denitrification, has been found in cultures maintained at dissolved oxygen concentrations up to 90% of air saturation.

The evidence for aerobic denitrification was obtained from a number of independant experiments. Denitrifying enzymes were present even in organisms growing aerobically without nitrate. Aerobic yields on acetate were higher (8.1 g protein/mol) without than with (6.0 g protein/mol) nitrate, while the anaerobic yield with nitrate was even lower (4 g protein/mol). The maximum specific growth rate of Tsa. pantotropha was higher (0.34 h-1) in the presence of both oxygen (>80% air saturation) and nitrate than in similar cultures not supplied with nitrate (0.27 h-1), indicating that the rate of electron transport to oxygen was limiting. This was confirmed by oxygen uptake experiments which showed that although the rate of respiration on acetate was not affected by nitrate, the total oxygen uptake was reduced in its presence. The original oxygen uptake could be restored by the addition of denitrification inhibitors.

Key words

Aerobic denitrification Thiosphaera pantotropha Nitrate reduction Bacterial selection Ecology Oxygen 

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Lesley A. Robertson
    • 1
  • J. Gijs Kuenen
    • 1
  1. 1.Laboratory of MicrobiologyDelft University of TechnologyDelftThe Netherlands

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