Fig. 6. Schematic overview of the fructose metabolism of A. woodii using caffeate as final electron acceptor and growth of A. woodii wild type and the hydBA mutant on different carbon sources with caffeate as electron acceptor.

Fd, ferredoxin; Fd²⁻, reduced ferredoxin (a). Cells were grown in complex medium supplemented with either 20 mM fructose + 6 mM caffeate (b), 80 mM lactate + 4 mM caffeate (c) or 50 mM ethanol + 4 mM caffeate (d). Growth of the wild type + caffeate (■), hydBA mutant + caffeate (▲), wild type without caffeate (□), hydBA mutant without caffeate (△) were measured over time at 600 nm. Caffeate was added when concentrations dropped below 1 mM and its utilisation by the wild type (×) and hydBA mutant  (+) was monitored over time (n = 2).