title: Effect of high electron donor supply on dissimilatory nitrate reduction pathways in a bioreactor for nitrate removal.
abstract: The possible shift of a bioreactor for NO3(-) removal from predominantly denitrification (DEN) to dissimilatory nitrate reduction to ammonium (DNRA) by elevated electron donor supply was investigated. By increasing the C/NO3(-) ratio in one of two initially identical reactors, the production of high sulfide concentrations was induced. The response of the dissimilatory NO3(-) reduction processes to the increased availability of organic carbon and sulfide was monitored in a batch incubation system. The expected shift from a DEN- towards a DNRA-dominated bioreactor was not observed, also not under conditions where DNRA would be thermodynamically favorable. Remarkably, the microbial community exposed to a high C/NO3(-) ratio and sulfide concentration did not use the most energy-gaining process.
authors.affiliation: Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany. Electronic address: abehrend@mpi-bremen.de.
authors.forename: Anna
authors.initials: A
authors.lastname: Behrendt
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion, Haifa, Israel.
authors.forename: Sheldon
authors.initials: S
authors.lastname: Tarre
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion, Haifa, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Beliavski
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion, Haifa, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Green
authors.affiliation: Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Klatt
authors.affiliation: Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: de Beer
authors.affiliation: Max Planck Institute for Marine Microbiology, Microsensor Group, Bremen, Germany; University of Southern Denmark, Department of Biology, NordCEE, Odense, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Stief
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D004583:Electrons; D007700:Kinetics; D009566:Nitrates / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D009587:Nitrogen Isotopes / Q000032:analysis; D010084:Oxidation-Reduction; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D009587:Nitrogen Isotopes; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Dissimilatory nitrate reduction; Microbial aggregates; Sulfide; USB reactor