title: Proteomic Analysis of the Hydrogen and Carbon Monoxide Metabolism of Methanothermobacter marburgensis.
abstract: Hydrogenotrophic methanogenic archaea are efficient H2 utilizers, but only a few are known to be able to utilize CO. Methanothermobacter thermoautotrophicus is one of the hydrogenotrophic methanogens able to grow on CO, albeit about 100 times slower than on H2 + CO2. In this study, we show that the hydrogenotrophic methanogen Methanothermobacter marburgensis, is able to perform methanogenic growth on H2/CO2/CO and on CO as a sole substrate. To gain further insight in its carboxydotrophic metabolism, the proteome of M. marburgensis, grown on H2/CO2 and H2/CO2/CO, was analyzed. Cultures grown with H2/CO2/CO showed relative higher abundance of enzymes involved in the reductive acetyl-CoA pathway and proteins involved in redox metabolism. The data suggest that the strong reducing capacity of CO negatively affects hydrogenotrophic methanogenesis, making growth on CO as a sole substrate difficult for this type of methanogens. M. marburgensis appears to partly deal with this by up-regulating co-factor regenerating reactions and activating additional pathways allowing for formation of other products, like acetate.
authors.affiliation: Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Diender
authors.affiliation: Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pereira
authors.affiliation: Department of Laboratory Medicine, Radboud University Medical Center Nijmegen, Netherlands.
authors.forename: Hans J C T
authors.initials: HJ
authors.lastname: Wessels
authors.affiliation: Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands; Centre of Biological Engineering, University of MinhoBraga, Portugal.
authors.forename: Alfons J M
authors.initials: AJ
authors.lastname: Stams
authors.affiliation: Laboratory of Microbiology, Wageningen University Wageningen, Netherlands.
authors.forename: Diana Z
authors.initials: DZ
authors.lastname: Sousa
keywords: CODH; Methanothermobacter thermoautotrophicus; methanogenesis; reductive acetyl-CoA pathway; syngas