Fig. 1.

The Wood–Ljungdahl pathway of CO₂ reduction. In the WLP, two molecules of CO₂ are reduced to the central intermediate acetyl‐CoA. Entry points for other C1 substrates are indicated. Acetyl‐CoA is the precursor of biomass and a wide range of natural products (blue). The pathways leading from acetyl‐CoA to products are not complete and miss intermediates, reducing equivalents and ATP input/output. Only the pathway leading to butyrate is complete. CoFeSP, corrinoid/iron sulfur protein; THF, tetrahydrofolate; CoA, coenzyme A; [H], reducing equivalent.