Related Experiment Video
Updated: May 30, 2026
09:11
Evaluating the Impact of Hydraulic Fracturing on Streams using Microbial Molecular Signatures
Published on: April 4, 2021
Watershed urbanization alters the composition and function of stream bacterial communities
Si-Yi Wang1, Elizabeth B Sudduth, Matthew D Wallenstein
1Biology Department, Duke University, Durham, North Carolina, United States of America. sw56@duke.edu
Plos One
|August 23, 2011
Summary
Urbanization alters stream microbial communities, impacting crucial functions like denitrification. Bacterial community composition shifts significantly with urbanization, affecting ecosystem processes in streams.
Area of Science:
- Environmental microbiology
- Stream ecology
- Urban hydrology
Background:
- Watershed urbanization causes significant physical and chemical changes in streams.
- Urban streams experience scouring flows, pollution, and habitat alteration.
- Impacts of urbanization on stream microbial communities and ecosystem functions remain poorly understood.
Purpose of the Study:
- To investigate how watershed urbanization affects stream bacterial community composition.
- To assess the impact of urbanization on denitrification, a key microbial process.
- To link bacterial community structure to ecosystem function in urban streams.
Main Methods:
- Repeated sediment sampling from eight streams across an urbanization gradient over two years.
- Characterization of overall and denitrifying bacterial communities using molecular methods.
- Measurement of denitrification potentials and substrate supply (nitrate, organic carbon).
Main Results:
- Bacterial community composition, both overall and denitrifying, strongly correlated with the urbanization gradient.
- Denitrification potentials varied widely but were not directly explained by substrate availability alone.
- A mixed-effects model incorporating bacterial community composition and substrate supply explained 45% of the variation in denitrification potential.
Conclusions:
- Watershed urbanization drives significant shifts in stream bacterial community composition.
- Changes in microbial communities due to urbanization can have substantial consequences for ecosystem functions, such as denitrification.
- Understanding these microbial shifts is crucial for managing urban aquatic ecosystems.
Related Concept Videos
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
01:30Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
01:29Soil Microbial Ecology
Soil microbial ecology is defined by highly diverse, spatially structured communities that drive nutrient cycling, organic matter turnover, and overall ecosystem stability. Although a gram of soil can contain thousands of bacterial and archaeal taxa, the ecological processes they mediate are even more crucial for sustaining terrestrial life.Microhabitats and NichesSoil is a heterogeneous mixture of minerals, organic matter, water, and air. Microbes inhabit distinct microhabitats formed by...
01:21Microbiota Modulation by Antibiotics
Antibiotics have revolutionized modern medicine by saving countless lives from bacterial infections. However, their widespread use has inadvertently harmed the delicate balance of the human gut microbiota. The gut microbiota, a complex community of bacteria, archaea, viruses, and fungi, plays a vital role in regulating metabolism, immune responses, and maintaining intestinal health. Antibiotics, especially broad-spectrum types, disrupt this ecosystem by eradicating both harmful and beneficial...
01:28Introduction to Microbial Ecology
Microbial ecology examines the complex web of interactions and diversity among microorganisms within various ecosystems. This field seeks to understand how microbial populations adapt to and influence their environments and how these interactions shape broader ecological processes. Microbes are integral to ecosystem function, participating in nutrient cycling, energy flow, and the maintenance of environmental homeostasis.An ecosystem represents a dynamic interaction between living organisms...