Metabolic engineering of a 1,2-propanediol pathway in Escherichia coli.
1,2-Propanediol (1,2-PD) is a major commodity chemical that is currently derived from propylene, a nonrenewable resource. A goal of our research is to develop fermentation routes to 1,2-PD from renewable resources. Here we report the production of enantiomerically pure R-1,2-PD from glucose in Escherichia coli expressing NADH-linked glycerol dehydrogenase genes (E. coli gldA or Klebsiella pneumoniae dhaD). We also show that E. coli overexpressing the E. coli methylglyoxal synthase gene (mgs) produced 1,2-PD. The expression of either glycerol dehydrogenase or methylglyoxal synthase resulted in the anaerobic production of approximately 0.25 g of 1,2-PD per liter. R-1,2-PD production was further improved to 0.7 g of 1,2-PD per liter when methylglyoxal synthase and glycerol dehydrogenase (gldA) were coexpressed. In vitro studies indicated that the route to R-1,2-PD involved the reduction of methylglyoxal to R-lactaldehyde by the recombinant glycerol dehydrogenase and the reduction of R-lactaldehyde to R-1, 2-PD by a native E. coli activity. We expect that R-1,2-PD production can be significantly improved through further metabolic and bioprocess engineering.
Department of Chemical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691, USA.
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D000693:Anaerobiosis; D019757:Carbon-Oxygen Lyases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D005285:Fermentation; D005818:Genetic Engineering; D005947:Glucose / Q000378:metabolism; D007544:Isopropyl Thiogalactoside / Q000378:metabolism; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000235:genetics; D019946:Propylene Glycol / Q000737:chemistry / Q000378:metabolism*; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D014169:Transformation, Bacterial
D007544:Isopropyl Thiogalactoside; D019946:Propylene Glycol; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D019757:Carbon-Oxygen Lyases; C021578:methylglyoxal synthase; D005947:Glucose