Carbon monoxide conversion by anaerobic bioreactor sludges

Seven different anaerobic sludges from wastewater treatment reactors were screened for their ability to convert carbon monoxide (CO) at 30 and 55degreesC. At 30degreesC, CO was converted to methane and/or acetate by all tested sludges. Inhibition experiments, using 2-bromoethanesulfonic acid and vancomycine, showed that CO conversion to methane at 30degreesC occurred via acetate, but not via H-2. At 55degreesC, four sludges originally cultivated at 30-35degreesC and one sludge cultivated at 55degreesC converted CO rapidly into hydrogen or into methane. In the latter case, inhibition experiments showed that methane was formed via hydrogen as the intermediate. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.