Semiphosphorylative Entner-Duodoroff pathway as it operates in A. schaalii.

This pathway involves either oxidation of glucose by the membrane-bound glucose dehydrogenase (gdh) to form glucono-1,5-lactone which is then converted to gluconate by gluconolactonase or gluconate is taken up by the cell via a putative gluconate permease (GntP). Gluconate is then converted to 2-keto-3-deoxygluconate (KDG) by a specific gluconate dehydratase (ILVD_EDD). Further metabolism of KDG involves its phosphorylation by KDG kinase to form KDPG, followed by cleavage by EDA to pyruvate and glyceraldehyde-3-phosphate. Glyceraldehyde-3-phosphate is further converted to form another pyruvate molecule via common reaction of the EM pathway. A similar modified ED pathway has been shown to occur in several Clostridium species e.g. Clostridium aceticum [49] and halophilic archaea, e.g. Halobacterium saccharovorum [50]. Abbreviations: gdh, glucose-1-dehydrogenase; gnl, gluconolactonase; ilvD/EDD, dihydroxyacid dehydratase; KDGK, 2-dehydro-3-deoxygluconokinase; EDA, 2-dehydro-3-deoxyphosphogluconate aldolase; GAP, glyceraldehyde 3-phosphate dehydrogenase; PGM, phosphoglycerate mutase; ENO, enolase; PYK, pyruvate kinase.