Aerobic denitrifiers isolated from an alternating activated sludge system

Authors

  • Lone Frette,

    1. Department of General Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark
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  • Bo Gejlsbjerg,

    1. Department of General Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark
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  • Peter Westermann

    Corresponding author
    1. Department of General Microbiology, University of Copenhagen, Sølvgade 83H, 1307 Copenhagen K, Denmark
      Corresponding author. Tel.: +45 35 32 20 46; Fax: +45 35 32 20 40; E-mail: pew@mermaid.molbio.ku.dk
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Corresponding author. Tel.: +45 35 32 20 46; Fax: +45 35 32 20 40; E-mail: pew@mermaid.molbio.ku.dk

Abstract

One hundred and sixty-nine bacterial strains were isolated from activated sludge from a waste water treatment basin operating under alternating aerobic/anaerobic conditions. Sixteen strains from a subsample of 23 nitrogen oxide reducers were true respiratory denitrifiers, and all denitrified under both anaerobic and aerobic conditions. REP-PCR band analysis showed different patterns for all strains. One strain (strain 1) produced large amounts of N2O and was studied in detail. Nitrous oxide was the major end product of denitrification by this strain, and NO2 was reduced more efficiently than NO3. The aerobic denitrification was most pronounced with NO2 as electron acceptor, and the reduction of NO2 was not coupled to NH+4 oxidation.

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