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The impact and fate of clarithromycin in anaerobic digestion of waste activated sludge for biogas production
- Source :
- Environmental research. 195
- Publication Year :
- 2020
-
Abstract
- Clarithromycin retained in waste activated sludge (WAS) inevitably enters the anaerobic digestion system. So far, the complex impacts and fate of clarithromycin in continuous operated WAS anaerobic digestion system are still unclear. In this study, two semi-continuous long-term reactors were set up to investigate the effect of clarithromycin on biogas production and antibiotic resistance genes (ARGs) during WAS anaerobic digestion, and a batch test was carried out to explore the potential metabolic mechanism. Experimental results showed that clarithromycin at lower concentrations (i.e., 0.1 and 1.0 mg/L) did not affect biogas production, whereas the decrease in biogas production was observed when the concentration of clarithromycin was further increased to 10 mg/L. Correspondingly, the relative abundance of functional bacteria in WAS anaerobic digestion (i.e., Anaerolineaceae and Microtrichales) was reduced with long-term clarithromycin exposure. The investigation of ARGs suggested that the effect of methylation belonging to the target site modification played a critical role for the anaerobic microorganisms in the expression of antibiotic resistance, and ermF, played dominated ARGs, presented the most remarkable proliferation. In comparison, the role of efflux pump was weakened with a significant decrease of two detected efflux genes. During WAS anaerobic digestion, clarithromycin could be partially degraded into metabolites with lower antimicrobial activity including oleandomycin and 5-O-desosaminyl-6-O-methylerythronolide and other metabolites without antimicrobial activity.
- Subjects :
- 010501 environmental sciences
Toxicology
01 natural sciences
Biochemistry
03 Chemical Sciences, 05 Environmental Sciences, 06 Biological Sciences
03 medical and health sciences
0302 clinical medicine
Bioreactors
Clarithromycin
medicine
030212 general & internal medicine
Food science
Anaerobiosis
0105 earth and related environmental sciences
General Environmental Science
Oleandomycin
biology
Sewage
Chemistry
Drug Resistance, Microbial
Metabolism
biology.organism_classification
Antimicrobial
Anaerobic digestion
Activated sludge
Biofuels
Efflux
Bacteria
medicine.drug
Subjects
Details
- ISSN :
- 10960953
- Volume :
- 195
- Database :
- OpenAIRE
- Journal :
- Environmental research
- Accession number :
- edsair.doi.dedup.....81d1cdf2d84e597db618ac8e6cab0a09