title: Influence of process dynamics on the microbial diversity in a nitrifying biofilm reactor: Correlation analysis and simulation study.
abstract: For engineers, it is interesting to gain insight in the effect of control strategies on microbial communities, on their turn influencing the process behavior and its stability. This contribution assesses the influence of process dynamics on the microbial community in a biofilm reactor for nitrogen removal, which was controlled according to several strategies aiming at nitrite accumulation. The process dataset, combining conventional chemical and physical data with molecular information, was analyzed through a correlation analysis and in a simulation study. During nitrate formation, an increased nitrogen loading rate (NLR) resulted in a drop of the bulk liquid oxygen concentration without resulting in nitrite accumulation. A biofilm model was able to reproduce the bulk liquid nitrogen concentrations in two periods before and after this increased NLR. As the microbial parameters calibrated for the ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in both periods were different, it was concluded that the increased NLR governed an AOB and NOB population shift. Based on the molecular data, it was assumed that each period was typified by one dominant AOB and probably several subdominant NOB populations. The control strategies for nitrite accumulation influenced the bulk liquid composition by controlling the competition between AOB and NOB. Biotechnol. Bioeng. 2016;113: 1962-1974. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Biosystems Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
authors.forename: Thomas P W
authors.initials: TP
authors.lastname: Vannecke
authors.affiliation: Laboratoire de Biotechnologie de l'Environnement, INRA, UR0050, Narbonne, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bernet
authors.affiliation: Department of Biosystems Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
authors.forename: Mari K H
authors.initials: MK
authors.lastname: Winkler
authors.affiliation: Laboratoire de Biotechnologie de l'Environnement, INRA, UR0050, Narbonne, France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: Santa-Catalina
authors.affiliation: Laboratoire de Biotechnologie de l'Environnement, INRA, UR0050, Narbonne, France.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Steyer
authors.affiliation: Department of Biosystems Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium. eveline.volcke@ugent.be.
authors.forename: Eveline I P
authors.initials: EI
authors.lastname: Volcke
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000378:metabolism*; D018441:Biofilms; D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D008954:Models, Biological; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*
chemical_list: D009584:Nitrogen
keywords: biofilm; control; dynamics; microbial diversity; modeling; nitrogen removal