Details

Autor(en) / Beteiligte

• Dottorini, Giulia
• Michaelsen, Thomas Yssing
• Kucheryavskiy, Sergey
• Andersen, Kasper Skytte
• Kristensen, Jannie Munk
• Peces, Miriam
• Wagner, Dorottya Sarolta
• Nierychlo, Marta
• Nielsen, Per Halkjær

Titel

Mass-immigration determines the assembly of activated sludge microbial communities

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2021-07, Vol.118 (27), p.1

Ort / Verlag

Washington: National Academy of Sciences

Erscheinungsjahr

2021

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Significance Wastewater treatment plants are engineering technologies used worldwide to protect the environment and human health. Microbial communities sustain these plants, so it is crucial to know the key factors responsible for the community assembly. We show, in contrast to existing understanding, that microbial immigration largely controls the community structure in these plants and that the fate (growth or death) of immigrating species in the plants is controlled by local factors. The community structure was quantitatively predicted by the immigrating microbial community, highlighting the need to revise the way we today understand, design, and manage microbial communities in wastewater treatment plants. The assembly of bacterial communities in wastewater treatment plants (WWTPs) is affected by immigration via wastewater streams, but the impact and extent of bacterial immigrants are still unknown. Here, we quantify the effect of immigration at the species level in 11 Danish full-scale activated sludge (AS) plants. All plants have different source communities but have very similar process design, defining the same overall environmental growth conditions. The AS community composition in each plant was strongly reflected by the corresponding influent wastewater (IWW) microbial composition. Most species in AS across the plants were detected and quantified in the corresponding IWW, allowing us to identify their fate in the AS: growing, disappearing, or surviving. Most of the abundant species in IWW disappeared in AS, so their presence in the AS biomass was only due to continuous mass-immigration. In AS, most of the abundant growing species were present in the IWW at very low abundances. We predicted the AS species abundances from their abundance in IWW by using a partial least square regression model. Some species in AS were predicted by their own abundance in IWW, while others by multiple species abundances. Detailed analyses of functional guilds revealed different prediction patterns for different species. We show, in contrast to the present understanding, that the AS microbial communities were strongly controlled by the IWW source community and could be quantitatively predicted by taking into account immigration. This highlights a need to revise the way we understand, design, and manage the microbial communities in WWTPs.