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Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
Published on: December 6, 2018
Biodegradation of atrazine under denitrifying conditions
J J Crawford1, G K Sims, R L Mulvaney
1Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana 61801, USA.
Applied Microbiology and Biotechnology
|July 3, 1998
Summary
The bacterial isolate M91-3 anaerobically degrades the herbicide atrazine, producing hydroxyatrazine and cleaving the ring. While M91-3 shows potential for bioreactors, indigenous microbes also biodegrade atrazine in sediments.
Area of Science:
- Environmental microbiology
- Bioremediation
- Agrochemical degradation
Background:
- Atrazine is a widely used herbicide with environmental persistence.
- Anaerobic biodegradation pathways for atrazine are crucial for its removal from contaminated environments.
- Bacterial isolates capable of atrazine degradation are key to developing bioremediation strategies.
Purpose of the Study:
- To characterize the anaerobic biodegradation of atrazine by the bacterial isolate M91-3.
- To investigate the potential of M91-3 to enhance atrazine biodegradation in anaerobic sediment.
- To assess the application of M91-3 in fixed-film bioreactors for atrazine and nitrate removal.
Main Methods:
- Utilized fixed-film (glass beads) batch column systems under anoxic conditions.
- Employed High-Performance Liquid Chromatography (HPLC) and Thin-Layer Chromatography (TLC) radiochromatography.
- Monitored mineralization via 14CO2 evolution and denitrification via 15N2 detection.
Main Results:
- Bacterial isolate M91-3 utilized atrazine as its sole carbon and nitrogen source.
- Anaerobic biotransformation yielded hydroxyatrazine, followed by ring cleavage.
- Denitrification was confirmed in amended cultures.
- M91-3 inoculation did not significantly enhance atrazine mineralization in sediments, indicating the presence of indigenous degraders.
Conclusions:
- Bacterial isolate M91-3 effectively degrades atrazine anaerobically, forming hydroxyatrazine and mineralizing the compound.
- The presence of indigenous anaerobic atrazine-degrading organisms in sediments was suggested.
- Fixed-film bioreactors using M91-3 show promise for removing atrazine and nitrate from aqueous media.
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