title: Effect of carbon monoxide, hydrogen and sulfate on thermophilic (55 degrees C) hydrogenogenic carbon monoxide conversion in two anaerobic bioreactor sludges.
abstract: The conversion routes of carbon monoxide (CO) at 55 degrees C by full-scale grown anaerobic sludges treating paper mill and distillery wastewater were elucidated. Inhibition experiments with 2-bromoethanesulfonate (BES) and vancomycin showed that CO conversion was performed by a hydrogenogenic population and that its products, i.e. hydrogen and CO2, were subsequently used by methanogens, homo-acetogens or sulfate reducers depending on the sludge source and inhibitors supplied. Direct methanogenic CO conversion occurred only at low CO concentrations [partial pressure of CO (PCO) <0.5 bar (1 bar=10(5) Pa)] with the paper mill sludge. The presence of hydrogen decreased the CO conversion rates, but did not prevent the depletion of CO to undetectable levels (<400 ppm). Both sludges showed interesting potential for hydrogen production from CO, especially since after 30 min exposure to 95 degrees C, the production of CH4 at 55 degrees C was negligible. The paper mill sludge was capable of sulfate reduction with hydrogen, tolerating and using high CO concentrations (PCO>1.6 bar), indicating that CO-rich synthesis gas can be used efficiently as an electron donor for biological sulfate reduction.
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Bomenweg 2, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. jan.sipma@wur.nl
authors.forename: J
authors.initials: J
authors.lastname: Sipma
authors.forename: R J W
authors.initials: RJ
authors.lastname: Meulepas
authors.forename: S N
authors.initials: SN
authors.lastname: Parshina
authors.forename: A J M
authors.initials: AJ
authors.lastname: Stams
authors.forename: G
authors.initials: G
authors.lastname: Lettinga
authors.forename: P N L
authors.initials: PN
authors.lastname: Lens
mesh_terms: D000085:Acetates / Q000378:metabolism; D017738:Alkanesulfonic Acids / Q000494:pharmacology; D000693:Anaerobiosis; D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism*; D006131:Growth Inhibitors / Q000494:pharmacology; D006358:Hot Temperature; D006859:Hydrogen / Q000032:analysis / Q000378:metabolism*; D007218:Industrial Microbiology; D008697:Methane / Q000378:metabolism; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000085:Acetates; D017738:Alkanesulfonic Acids; D006131:Growth Inhibitors; D012722:Sewage; D013431:Sulfates; D002245:Carbon Dioxide; C018853:2-bromoethanesulfonic acid; D014640:Vancomycin; D002248:Carbon Monoxide; D006859:Hydrogen; D008697:Methane