title: Effect of sludge age on population dynamics and acetate utilization kinetics under aerobic conditions.
abstract: The study addressed acetate utilization by an acclimated mixed microbial culture under different growth conditions. It explored changes in the composition of the microbial community and variable process kinetics induced by different culture history. Sequencing batch reactors were operated at steady-state at different sludge ages of two and ten days. Microbial population structure was determined using high-throughput sequencing of 16S rRNA genes. Parallel batch experiments were conducted with acclimated biomass for respirometric analyses. A lower sludge age sustained a different community, which also reflected as variable kinetics for microbial growth and biopolymer storage. The maximum growth rate was observed to change from 3.9/d to 8.5/d and the substrate storage rate from 3.5/d to 5.9/d when the sludge age was decreased from 10 d to 2.0 d. Results challenge the basic definition of heterotrophic biomass in activated sludge models, at least by means of variable kinetics under different growth conditions.
authors.affiliation: Istanbul Technical University, Faculty of Civil Engineering, Environmental Engineering Department, Maslak, Istanbul TR-34469, Turkey. ilkepala@gmail.com
authors.forename: Ilke
authors.initials: I
authors.lastname: Pala-Ozkok
authors.forename: Ateequr
authors.initials: A
authors.lastname: Rehman
authors.forename: Gokce
authors.initials: G
authors.lastname: Kor-Bicakci
authors.forename: Aslihan
authors.initials: A
authors.lastname: Ural
authors.forename: Markus B
authors.initials: MB
authors.lastname: Schilhabel
authors.forename: Emine
authors.initials: E
authors.lastname: Ubay-Cokgor
authors.forename: Daniel
authors.initials: D
authors.lastname: Jonas
authors.forename: Derin
authors.initials: D
authors.lastname: Orhon
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000332:Aerobiosis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008962:Models, Theoretical; D010100:Oxygen / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000382:microbiology
chemical_list: D000085:Acetates; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010100:Oxygen
keywords: Acetate; Activated Sludge Modeling; Microbial population; Process kinetics; Pyrosequencing