Molecular Breeding of Advanced Microorganisms for Biofuel Production

Figure 6

Synthetic pathway of isobutanol through keto-acid pathway. Numbers refer to the enzymes; 1: acetolactate synthase (AlsS), 2: acetohydroxy acid isomeroreductase (IlvC), 3: dihydroxy-acid dehydratase (IlvD), 4: 2-ketoacid decarboxylase (KDC), 5: alcohol dehydrogenase (ADH).