Three-dimensional stratification of bacterial biofilm populations in a moving bed biofilm reactor for nitritation-anammox.
Journal article, 2014

Moving bed biofilm reactors (MBBRs) are increasingly used for nitrogen removal with nitritation-anaerobic ammonium oxidation (anammox) processes in wastewater treatment. Carriers provide protected surfaces where ammonia oxidizing bacteria (AOB) and anammox bacteria form complex biofilms. However, the knowledge about the organization of microbial communities in MBBR biofilms is sparse. We used new cryosectioning and imaging methods for fluorescence in situ hybridization (FISH) to study the structure of biofilms retrieved from carriers in a nitritation-anammox MBBR. The dimensions of the carrier compartments and the biofilm cryosections after FISH showed good correlation, indicating little disturbance of biofilm samples by the treatment. FISH showed that Nitrosomonas europaea/eutropha-related cells dominated the AOB and Candidatus Brocadia fulgida-related cells dominated the anammox guild. New carriers were initially colonized by AOB, followed by anammox bacteria proliferating in the deeper biofilm layers, probably in anaerobic microhabitats created by AOB activity. Mature biofilms showed a pronounced three-dimensional stratification where AOB dominated closer to the biofilm-water interface, whereas anammox were dominant deeper into the carrier space and towards the walls. Our results suggest that current mathematical models may be oversimplifying these three-dimensional systems and unless the multidimensionality of these systems is considered, models may result in suboptimal design of MBBR carriers.

anammox

AOB

stratification

moving bed biofilm reactor (MBBR)

wastewater

biofilm

nitritation

Author

Robert Almstrand

University of Gothenburg

Frank Persson

Chalmers, Civil and Environmental Engineering, Water Environment Technology

Holger Daims

University of Vienna

Maria Ekenberg

AnoxKaldnes AB

Magnus Christensson

AnoxKaldnes AB

Britt-Marie Wilen

Chalmers, Civil and Environmental Engineering, Water Environment Technology

Fred Sörensson

University of Gothenburg

Malte Hermansson

University of Gothenburg

International Journal of Molecular Sciences

16616596 (ISSN) 14220067 (eISSN)

Vol. 15 2 2191-206

Driving Forces

Sustainable development

Areas of Advance

Building Futures (2010-2018)

Roots

Basic sciences

Subject Categories

Microbiology

Water Treatment

DOI

10.3390/ijms15022191

PubMed

24481066

More information

Latest update

3/29/2018