title: Kinetics, diffusional limitation and microscale distribution of chemistry and organisms in a CANON reactor.
abstract: In the Completely Autotrophic Nitrogen removal Over Nitrite (CANON) process, aerobic and anaerobic ammonia oxidizing bacteria cooperate to remove ammonia in one oxygen-limited reactor. Kinetic studies, microsensor analysis, and fluorescence in situ hybridization on CANON biomass showed a partial differentiation of processes and organisms within and among aggregates. Under normal oxygen-limited conditions ( approximately 5 microM O2), aerobic ammonia oxidation (nitrification) was restricted to an outer shell (<100 microm) while anaerobic ammonia oxidation (anammox) was found in the central anoxic parts. Larger type aggregates (>500 microm) accounted for 68% of the anammox potential whereas 65% of the nitrification potential was found in the smaller aggregates (<500 microm). Analysis with O2 and NO2- microsensors showed that the thickness of the activity zones varied as a function of bulk O2 and NO2- concentrations and flow rate.
authors.affiliation: Department of Microbiology, University of Aarhus, Ny Munkegade, Bldg. 540, 8000 Aarhus C, Denmark. mnielsen@biology.au.dk
authors.forename: Michael
authors.initials: M
authors.lastname: Nielsen
authors.forename: Annette
authors.initials: A
authors.lastname: Bollmann
authors.forename: Olav
authors.initials: O
authors.lastname: Sliekers
authors.forename: Mike
authors.initials: M
authors.lastname: Jetten
authors.forename: Markus
authors.initials: M
authors.lastname: Schmid
authors.forename: Marc
authors.initials: M
authors.lastname: Strous
authors.forename: Ingo
authors.initials: I
authors.lastname: Schmidt
authors.forename: Lars Hauer
authors.initials: LH
authors.lastname: Larsen
authors.forename: Lars Peter
authors.initials: LP
authors.lastname: Nielsen
authors.forename: Niels Peter
authors.initials: NP
authors.lastname: Revsbech
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000378:metabolism; D000693:Anaerobiosis; D001420:Bacteria, Aerobic / Q000378:metabolism; D001421:Bacteria, Anaerobic / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D004058:Diffusion; D007700:Kinetics; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism
chemical_list: D009573:Nitrites; D000641:Ammonia; D010100:Oxygen