Fig. 1
From: Electrode-assisted acetoin production in a metabolically engineered Escherichia coli strain
Scheme of an unbalanced fermentation. An unbalanced fermentation integrates two elements: First, the metabolism of a production organism is engineered in such a way, that only one desired substance is produced. As a consequence, redox equivalents like NAD+ cannot be regenerated anymore. The second element is the bioelectrochemical reactor supplying the organisms with an anode as a non-depletable electron acceptor