Combined deterministic and stochastic processes control microbial succession in replicate granular biofilm reactors
Journal article, 2019

Granular sludge is an efficient and compact biofilm process for wastewater treatment. However, the ecological factors involved in microbial community assembly during the granular biofilm formation are poorly understood and little is known about the reproducibility of the process. Here, three replicate bioreactors were used to investigate microbial succession during the formation of granular biofilms. We identified three successional phases. During the initial phase, the successional turnover was high and α-diversity decreased as a result of the selection of taxa adapted to grow on acetate and form aggregates. Despite these dynamic changes, the microbial communities in the replicate reactors were similar. The second successional phase occurred when the settling time was rapidly decreased to selectively retain granules in the reactors. The influence of stochasticity on succession increased and new niches were created as granules emerged, resulting in temporarily increased α-diversity. The third successional phase occurred when the settling time was kept stable and granules dominated the biomass. Turnover was low and selection resulted in the same abundant taxa in the reactors, but drift, which mostly affected low-abundant community members, caused the community in one reactor to diverge from the other two. Even so, performance was stable and similar between reactors.

microbial community dynamics

null models

deterministic factors

Granular sludge

stochastic factors

ecological processess

biofilm

diversity

Author

Raquel Liebana

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Oskar Modin

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Frank Persson

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Enikö Barbara Szabo

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Malte Hermansson

Britt-Marie Wilen

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Environmental Science & Technology

0013-936X (ISSN) 1520-5851 (eISSN)

Subject Categories

Biochemistry and Molecular Biology

Ecology

Environmental Sciences

DOI

10.1021/acs.est.8b06669

PubMed

30969774

More information

Latest update

5/24/2019