FIG. 1.

Postulated pathway of anaerobic phenol metabolism in the denitrifying bacterium T. aromatica. E1, phenylphosphate synthase; E2, phenylphosphate carboxylase (the mechanism by which the phenolate anion is bound to the enzyme E2 is unknown so far); E3, 4-hydroxybenzoate-CoA ligase; E4, 4-hydroxybenzoyl-CoA reductase (dehydroxylating, ferredoxin dependent); E5, benzoyl-CoA reductase (dearomatizing, ferredoxin dependent). For further metabolism of benzoyl-CoA to three acetyl-CoA, one CO₂, and six H molecules, see reference 25. Fd, ferredoxin. X∼P, phosphoryl donor, unknown so far.