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Published on: October 15, 2015
Carbon monoxide conversion by anaerobic bioreactor sludges
Jan Sipma1, Piet N L Lens, Alfons J M Stams
1Sub-Department of Environmental Technology, Wageningen University, Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. jan.sipma@wur.nl
FEMS Microbiology Ecology
|September 2, 2009
Summary
Anaerobic sludges convert carbon monoxide (CO) to methane and acetate at 30°C, primarily via acetate. At 55°C, some sludges convert CO to methane or hydrogen, with methane formation occurring via hydrogen intermediates.
Area of Science:
- Microbiology
- Environmental Science
- Biotechnology
Background:
- Anaerobic digestion is crucial for wastewater treatment.
- Carbon monoxide (CO) is a potential substrate for microbial conversion.
- Understanding microbial pathways for CO conversion is vital for optimizing biogas production.
Purpose of the Study:
- To investigate the capacity of anaerobic sludges to convert carbon monoxide (CO).
- To determine the optimal temperature for CO conversion by different anaerobic sludges.
- To elucidate the metabolic pathways involved in CO conversion to methane and acetate.
Main Methods:
- Screening of seven anaerobic sludges from wastewater treatment reactors.
- Incubation of sludges with CO at two different temperatures (30°C and 55°C).
- Inhibition experiments using 2-bromoethanesulfonic acid and vancomycine to identify metabolic intermediates.
Main Results:
- All tested sludges converted CO to methane and/or acetate at 30°C.
- CO conversion to methane at 30°C proceeded via acetate, not H2.
- At 55°C, four sludges (30-35°C cultivated) and one sludge (55°C cultivated) rapidly converted CO to hydrogen or methane.
- Methane formation at 55°C occurred via hydrogen as an intermediate.
Conclusions:
- Anaerobic sludges exhibit diverse CO conversion capabilities dependent on temperature.
- Acetate and hydrogen serve as key intermediates in the microbial conversion of CO to methane.
- Optimizing temperature and understanding microbial pathways can enhance CO utilization in anaerobic digestion.
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