TABLE 2.

Hydrogenase and formate dehydrogenase specific activities in cell extracts of S. fumaroxidans and formate-H2 lyase activities in intact S. fumaroxidans cellsa

SubstrateActivity (U/mg)
Formate dehydrogenaseHydrogenaseFormate H2-lyase (cells)
Propionate (syntrophic growth)198280.037
Propionate-fumarate60160.059
Propionate-sulfate3111NDb
H2-sulfate16120.027
Fumarate-formate5.47.2ND
Fumarate-H26.93.5ND
Fumarate255.50.062
Pyruvate10332ND
  • a Syntrophically grown S. fumaroxidans cells were separated from M. hungatei cells by Percoll gradient centrifugation. Formate-H2 lyase and benzyl viologen-dependent oxidation activities were measured at 37°C and pH 8.

  • b ND, not determined.