Fig. 4

Metabolic pathways for the production of 1,2-propanediol (1,2-PDO). a Metabolic pathways for the production of 1,2-PDO from l-fucose and l-rhamnose; b metabolic pathways for the production of 1,2-PDO from glucose. Three pathways have been proposed to convert glucose into 1,2-PDO via either methylglyoxal (route ① illustrated by green colors and route ② illustrated by yellow colors) or lactate (route ③ illustrated by orange colors). ackA acetate kinase, adhE acetaldehyde/alcohol dehydrogenase, fucA d-fuculose 1-phosphate aldolase, fucI l-fucose isomerase, fucK fuculokinase, fucO NADH-dependent alcohol dehydrogenase, gloA glyoxalase I, ldhA lactate dehydrogenase, mgsA methylglyoxal synthase, pfl pyruvate formate lyase, pta phosphate acetyltransferase, rhaA l-rhamnose isomerase, rhaB l-rhamnulokinase, rhaD d-rhamnulose 1-phosphate aldolase