Levels of enzymes involved in the synthesis of acetate from CO2 in Clostridium thermoautotrophicum.

The acetogenic bacterium Clostridium thermoautotrophicum, grown on methanol, glucose, or CO2-H2, contained high levels of corrinoids, formate dehydrogenase, tetrahydrofolate enzymes, carbon monoxide dehydrogenase, and hydrogenase. Cell-free extracts catalyzed pyruvate-dependent formation of acetate from methyltetrahydrofolate. These results suggest that C. thermoautotrophicum synthesizes acetate from CO2 via a formate-tetrahydrofolate-corrinoid pathway.