title: Investigating biofilm structure developing on carriers from lab-scale moving bed biofilm reactors based on light microscopy and optical coherence tomography.
abstract: This study focused on characterizing the structure of biofilms developed on carriers used in lab-scale moving bed biofilm reactors. Both light microscopy (2D) and optical coherence tomography (OCT) were employed to track the biofilm development on carriers of different geometry and under different aeration rates. Biofilm structure was further characterized with respect to average biofilm thickness, biofilm growth velocity, biomass volume, compartment filling degree, surface area, etc. The results showed that carriers with a smaller compartment size stimulated a quick establishment of biofilms. Low aeration rates favored fast development of biofilms. Comparison between the results derived from 2D and 3D images revealed comparable results with respect to average biofilm thickness and compartment filling degree before the carrier compartments were fully willed with biomass. However, 3D imaging with OCT was capable of visualizing and quantifying the heterogeneous structure of biofilms, which cannot be achieved using 2D imaging.
authors.affiliation: Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Li
authors.affiliation: Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany; Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Felz
authors.affiliation: Institute of Functional Interfaces, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Urban Material Flow Management Technologies, Bauhaus-Institute for Infrastructure Solutions, Bauhaus University Weimar, Coudraystraße 7, 99421 Weimar, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Lackner
authors.affiliation: Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany; DVGW Research Laboratories Water Chemistry and Water Technology, Engler-Bunte-Ring 9, 76131 Karlsruhe, Germany. Electronic address: harald.horn@kit.edu.
authors.forename: Harald
authors.initials: H
authors.lastname: Horn
mesh_terms: D018441:Biofilms / Q000254:growth & development; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D021621:Imaging, Three-Dimensional; D008853:Microscopy; D041623:Tomography, Optical Coherence / Q000379:methods*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods
keywords: Biofilm structure; Light microscopy; Moving bed biofilm reactor; Optical coherence tomography; Structural parameter