The present study stratified excess activated sludge from six municipal wastewater treatment plants into four extracellular fractions including supernatant, slime, slightly-bond extracellular polymeric substances (LB-EPS) and tightly-bond EPS (TB-EPS) and one intracellular fraction (pellet) according to their different degrees of tight binding to sludge microbial aggregates and determined the abundance of seven antibiotic resistance genes (ARGs) (sul-I, sul-II, tet-C, tet-X, blaTEM, mefA and cat) and one mobile genetic elements (MGEs) (IntI-1) in each fraction. Extracellular ARGs were found to make up 0.1% - 74.2% of total ARGs, while the ratio of extracellular DNA to total DNA was only 1.2% - 4.2%, implying that EPS was a major ARG reservoir in sewage sludge. The genes of sul-I, tet-C and mefA have the highest mobility owing to a large proportion ranging from 0.5% to 32.7% in the fractions of LB-EPS, slime and supernatant, which indicates an increased risk of mediating the transfer of ARGs to environment. Comparatively, the proportion of blaTEM in the TB-EPS of sludge accounted for 0.3%-34.9% and caused limited-mobility. Sul-II, tet-X and cat and IntI-1, made up approximately 82.6% - 99.6% proportion in the cells, and were thus less mobile. This study proposes that ARGs and MGEs can have different mobilities. Those located in the outermost layers of sludge have a higher mobility potential of propagation into the natural environment during wastewater treatment and sludge utilization, leading to an increased risk of transferability.
The discrepant mobility of antibiotic resistant genes: Evidence from their spatial distribution in sewage sludge flocs.
P. He,Yizhou Zhou,L. Shao,Jinghua Huang,Zhan Yang,Fan Lü
Published 2019 in Science of the Total Environment
ABSTRACT
PUBLICATION RECORD
- Publication year
2019
- Venue
Science of the Total Environment
- Publication date
2019-12-20
- Fields of study
Medicine, Chemistry, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
- No claims are published for this paper.
CONCEPTS
- No concepts are published for this paper.
REFERENCES
Showing 1-50 of 50 references · Page 1 of 1
CITED BY
Showing 1-52 of 52 citing papers · Page 1 of 1