Fig. 9.

Metabolism of C. kluyveri. For the sake of simplicity, only the formation of butyrate and H₂ is shown. Reactions involved in caproate formation are analogous (butyryl-CoA condenses with acetyl-CoA). Ten mol NADH are consumed by the butyryl-CoA-DH complex. They are bifurcated to produce 5 mol butyryl-CoA and 5 mol Fd_red. Fd_red is either used by hydrogenase to produce H₂ or by Rnf to produce NADH and thereby generating an ion gradient. For further explanation, see text. [H] reducing equivalents, Fd ferredoxin, red reduced, ox oxidized