초록
<P><B>Abstract</B></P> <P>For the sustainable production of acetaldehyde, a key raw-material for a large number of chemical products, microbial production is a promising alternative. We have engineered an <I>Escherichia coli</I> strain for acetaldehyde production from glucose by introducing the pyruvate decarboxylase (Pdc) from <I>Zymomonas mobilis</I> and NADH oxidase (Nox) from <I>Lactococcus lactis</I>. Acetaldehyde production was systematically improved by knocking out the competing metabolic pathways. Multiple knockout strains were created and a final acetaldehyde titre of 0.73g/L was achieved using a quadruple knockout strain <I>E. coli</I> MC4100 <I>ΔadhE ΔldhA ΔfrdC ΔackA-pta</I>. In addition to acetaldehyde, about 0.37g/L acetoin was produced by these strains due to the additional carboligase activity exhibited by pyruvate decarboxylase resulting in a total carbon yield of 0.27g/g glucose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Acetaldehyde was produced in <I>E. coli</I> using pyruvate decarboxylase and NADH oxidase. </LI> <LI> Yield of acetaldehyde was improved by knocking down competing metabolic pathways. </LI> <LI> Major hurdle using pyruvate decarboxylase is its promiscuous carboligase activity. </LI> </UL> </P>