Understanding spatiotemporal patterns in microbial community composition is a central goal of microbial ecology. The objective of this study was to better understand the biogeography of activated sludge microbial communities, which are important for the protection of surface water quality. Monthly samples were collected from 20 facilities (25 bioreactors) within 442 km of each other for 1 year. Microbial community composition was characterized by sequencing of PCR-amplified 16S rRNA gene fragments. Statistically significant distance decay of community similarity was observed in these bioreactors independent of clustering method (operational taxonomic units [OTUs] at 97% similarity, genus-level phylotypes) and community dissimilarity metric (Sørensen, Bray-Curtis, and weighted Unifrac). Universal colonizers (i.e., detected in all samples) and ubiquitous genus-level phylotypes (i.e., detected in every facility at least once) also exhibited a significant distance decay relationship. Variation partitioning analysis of community composition showed that environmental characteristics (temperature, influent characteristics, etc.) explained more of the variance in community composition than geographic distance did, suggesting that environmental heterogeneity is more important than dispersal limitation as a mechanism for determining microbial community composition. Distance decay relationships also became stronger with increasing distance between facilities. Seasonal variation in community composition was also observed from selected bioreactors, but there was no clear seasonal pattern in the distance decay relationships.
Bibliographical noteFunding Information:
Financial support was provided by the Minnesota Environment and Natural Resources Trust Fund. We thank the operators at the treatment facilities for collecting samples and Elizabeth Hill for technical assistance.
© 2021 American Society for Microbiology. All rights reserved.
- Activated sludge
- Distance decay
- Microbial biogeography pattern
- Wastewater treatment
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't