title: Acclimation of denitrifying activated sludge to a single vs. complex external carbon source during a start-up of sequencing batch reactors treating ammonium-rich anaerobic sludge digester liquors.
abstract: In this study, denitrification of ammonium-reach anaerobic sludge digester liquor was investigated during start-up periods of two laboratory-scale "fill-and-draw" reactors. One reactor was fed with a single carbon source (ethanol), whereas the other reactor was fed with a complex carbon source (fusel oil). During two acclimation experiments, the structure of microbial community involved in denitrification was analyzed using 16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis fingerprints and fluorescent in situ hybridization. The characteristics of the mixed liquor were additionally supported by regular measurements of nitrate uptake rates. The addition of fusel oil and ethanol resulted in a significant enhancement of the denitrification rate and efficiency combined with the increasing volumetric addition of sludge digester liquor up to 15 % of the reactor volume. The microbiological analyses revealed that the addition of sludge digester liquor as well as both external carbon sources (fusel oil and ethanol) did not affect the structure of microbial communities in a severe way. In both reactors, Curvibacter sp. and Azoarcus sp. were found as the most abundant representatives of denitrifiers.
authors.affiliation: Faculty of Civil and Environmental Engineering, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233, Gdansk, Poland, kczer@pg.gda.pl.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Czerwionka
authors.forename: Aneta
authors.initials: A
authors.lastname: Luczkiewicz
authors.forename: Joanna
authors.initials: J
authors.lastname: Majtacz
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Kowal
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Jankowska
authors.forename: Slawomir
authors.initials: S
authors.lastname: Ciesielski
authors.forename: Krishna
authors.initials: K
authors.lastname: Pagilla
authors.forename: Jacek
authors.initials: J
authors.lastname: Makinia
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
chemical_list: D064751:Ammonium Compounds; D012722:Sewage; D002244:Carbon