초록
<P><B>Abstract</B></P> <P>In this study, the engineered <I>E. coli</I> was constructed for efficient transformation of glycerol to 1,3-propanediol (1,3-PDO). To regenerate NADPH, the key bottleneck in 1,3-PDO production, heterologous NADP<SUP>+</SUP>-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDN, encoded by <I>gapN</I>) pathway was introduced, and the <I>gapN</I> expression level was fine-tuned with specific 5′-untranslated regions (5′-UTR) to balance the carbon flux distribution between the metabolic pathways of NADPH regeneration and 1,3-PDO biosynthesis. Additionally, glucose was added to the medium to promote glycerol utilization and cell growth. To elevate the utilization of glycerol in the presence of glucose, <I>E. coli</I> JA11 was constructed through destroying PEP-dependent glucose transport system while strengthening the ATP-dependent transport system. Subsequent optimization of nitrogen sources further improved 1,3-PDO production. Finally, under the optimal fermentation condition, <I>E. coli</I> JA11 produced 13.47 g/L 1,3-PDO, with a yield of 0.64 mol/mol, increased by 325% and 100% compared with the original engineered <I>E. coli</I> JA03, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>E. coli</I> was engineered for transforming glycerol to 1,3-propanediol. </LI> <LI> The heterologous NADPH regeneration system was introduced into <I>E. coli</I>. </LI> <LI> Intracellular redox state was further optimized by fine-tuning <I>gapN</I> expression. </LI> <LI> Deleting <I>ptsG</I> and overexpressing <I>galP</I> and <I>glk</I> promoted substrates co-utilization. </LI> </UL> </P>