Fig. 5

The catabolism pathways for D-glucuronic acid, D-galacturonic acid, D-glucaric acid, and galactaric acid in bacteria. Enzymes: (1) uronate aldose-ketose isomerase (2) D-tagaturonate/D-fructuronate epimerase (3) D-fructuronate reductase (4) D-tagaturonate reductase (5) D-mannonate dehydratase (6) D-altronate dehydratase (7) 2-oxo-3-deoxy-D-gluconate kinase (8) 2-oxo-3-deoxy-6-phospho-D-gluconate aldolase (9) uronate dehydrogenase (10) galactaro δ-isomerase (11) spontaneous or lactonase (12) D-glucarate dehydratase (13) galactarate dehydratase (14) D-galactarolactone isomerase (15) 5-oxo-4-deoxy-D-glucarate aldolase (16) tartronate semialdehyde reductase (17) 5-oxo-4-deoxy-D-glucarate dehydratase (18) 2-oxoglutarate semialdehyde dehydrogenase. Reaction arrows indicated in green point to 2-oxo-3-deoxy-D-glucarate/5-oxo-4-deoxy-D-glucarate. The arrow in blue indicates a reaction from 5-oxo-4-deoxy-D-glucarate only. Red scissors indicate genes that were deleted, and green wrenches indicate genes that were expressed during metabolic engineering for the production of sugar acids