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Updated: Aug 26, 2025
Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris
Published on: July 28, 2018
The dangerous transporters: A study of microplastic-associated bacteria passing through municipal wastewater
Antonina Kruglova1, Barbara Muñoz-Palazón2, Alejandro Gonzalez-Martinez3
1Department of Built Environment, Aalto University, PO Box 15200, FI-00076, AALTO, Finland.
Abstract:
Microplastics (MPs) provide a stable and protective habitat for diverse wastewater bacteria, including pathogenic and antibiotic-resistant species. Therefore, MPs may potentially transport these bacteria through wastewater treatment steps to the environment and far distances. This study investigated bacterial communities of MP-associated bacteria from different stages of municipal wastewater treatment processes to evaluate the potential negative effect of these biofilms on the environment. The results showed a high diversity of bacteria that were strongly attached to MPs. After all treatment steps, the core bacterial groups remained attached to MPs and escaped from the wastewater treatment plant with effluent water. Several pathogenic bacteria were identified in MP samples from all treatment steps, and most of them were found in effluent water. These data provide new insights into the possible impacts of wastewater-derived MPs on the environment. MP-associated biofilms were proved to be important sources of pathogens and antibiotic-resistant genes in natural waters.
Insights
Microplastics (MPs) in wastewater act as rafts for diverse bacteria, including pathogens. These plastic particles can carry harmful microbes through treatment and into the environment.
Area of Science:
- Environmental microbiology
- Water quality research
- Microplastic pollution
Background:
- Microplastics (MPs) serve as biofilms, harboring diverse bacterial communities.
- Wastewater treatment plants (WWTPs) are potential hotspots for MP accumulation and bacterial colonization.
- MPs may facilitate the transport of pathogenic and antibiotic-resistant bacteria into aquatic environments.
Purpose of the Study:
- To investigate the bacterial communities associated with MPs at various stages of municipal WWTPs.
- To assess the role of MPs in the dissemination of bacteria, including pathogens and antibiotic-resistant strains, from WWTPs.
- To evaluate the potential environmental risks posed by MP-associated biofilms.
Main Methods:
- Sampling of MPs and associated bacterial communities from different stages of a municipal WWTP.
- Bacterial community analysis using molecular techniques (e.g., sequencing).
- Identification of specific bacterial species, including potential pathogens and antibiotic-resistant strains.
Main Results:
- High bacterial diversity was observed on MPs throughout the WWTP.
- Core bacterial groups remained attached to MPs, persisting through all treatment stages.
- Pathogenic bacteria were identified in MP samples from all treatment stages, with many detected in the final effluent.
Conclusions:
- Wastewater-derived MPs act as significant vectors for bacterial transport, including pathogens.
- MPs and their associated biofilms can escape WWTPs, potentially contaminating natural waters.
- MP-associated biofilms represent a crucial source of pathogens and antibiotic resistance genes in aquatic ecosystems.
