title: A low phosphorylation potential in the acetogen Acetobacterium woodii reflects its lifestyle at the thermodynamic edge of life.
abstract: The anaerobic, acetogenic bacterium Acetobacterium woodii grows on hydrogen and carbon dioxide and uses the Wood-Ljungdahl pathway to fix carbon but also to synthesize ATP. The free energy change of acetogenesis from H2 + CO2 allows for synthesis of only a fraction of an ATP under environmental conditions, and A. woodii is clearly a paradigm for microbial life under extreme energy limitation. However, it was unknown how much energy is required to make ATP under these conditions. In the present study, we determined the phosphorylation potential in cells metabolizing three different acetogenic substrates. It accounts to 37.9 ± 1.3 kJ/mol ATP during acetogenesis from fructose, 32.1 ± 0.3 kJ/mol ATP during acetogenesis from H2 + CO2 and 30.2 ± 0.9 kJ/mol ATP during acetogenesis from CO, the lowest phosphorylation potential ever described. The physiological consequences in terms of energy conservation under extreme energy limitation are discussed.
authors.affiliation: Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Spahn
authors.forename: Karsten
authors.initials: K
authors.lastname: Brandt
authors.forename: Volker
authors.initials: V
authors.lastname: Müller
mesh_terms: D045855:Acetobacterium / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis / Q000502:physiology*; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002248:Carbon Monoxide / Q000378:metabolism; D002478:Cells, Cultured; D005632:Fructose / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology*; D013816:Thermodynamics
chemical_list: D002245:Carbon Dioxide; D005632:Fructose; D002244:Carbon; D002248:Carbon Monoxide; D006859:Hydrogen; D000255:Adenosine Triphosphate