Fig. 2

Metabolic pathways for the production of ethylene glycol (EG). a Production of EG from glucose by serine-derived metabolic pathways. Two metabolic pathways have been proposed to convert serine into EG: ① (illustrated by green colors) serine dehydrogenase or transaminase (agt), α-keto acid decarboxylase (mdlC), and alcohol dehydrogenase (yqhD); ② (illustrated by yellow colors) serine decarboxylase (sdc), monoamine oxidase (ao), and alcohol dehydrogenase (yqhD) as route ①. b Production of EG from pentoses by different metabolic pathways. d-Xylose can be converted into EG by three proposed pathways: ③ (illustrated by orange colors) d-xylose dehydrogenase (xdh), d-xylonate dehydratase (yjhG/yagF), 2-dehydro-3-deoxy-d-xylonate aldolase (yjhH/yagE), and alcohol dehydrogenase (yqhD/fucO); ④ (illustrated by blue colors) xylose isomerase (xylA), hexokinase (khk-C), aldolase (aldoB), and alcohol dehydrogenase (yqhD/fucO) as route ③; ⑤ (illustrated by red colors) xylose isomerase (xylA) as route ④, d-tagatose epimerase (dte), fuculokinase (fucK), d-ribulose 1-phosphate aldolase (fucA/rhaD), and alcohol dehydrogenase (yqhD/fucO) as route ③. d-Arabinose can be converted into EG by l-fucose isomerase (fucI), fuculokinase (fucK), d-ribulose 1-phosphate aldolase (fucA/rhaD), and alcohol dehydrogenase (yqhD/fucO). l-Lyxose can be converted into EG by l-rhamnose isomerase (rhaA), l-rhamnulokinase (rhaB), d-ribulose 1-phosphate aldolase (fucA/rhaD), and alcohol dehydrogenase (yqhD/fucO). l-Arabinose can be converted into EG by l-arabinose isomerase (araA), d-tagatose epimerase (DTE), l-rhamnulokinase (rhaB), d-ribulose 1-phosphate aldolase (fucA/rhaD), and alcohol dehydrogenase (yqhD/fucO)