초록
<P><B>Abstract</B></P> <P>The capability of <I>Corynebacterium glutamicum</I> for glucose-based synthesis of itaconate was explored, which can serve as building block for production of polymers, chemicals, and fuels. <I>C. glutamicum</I> was highly tolerant to itaconate and did not metabolize it. Expression of the <I>Aspergillus terreus CAD1</I> gene encoding <I>cis</I>-aconitate decarboxylase (CAD) in strain ATCC13032 led to the production of 1.4mM itaconate in the stationary growth phase. Fusion of CAD with the <I>Escherichia coli</I> maltose-binding protein increased its activity and the itaconate titer more than two-fold. Nitrogen-limited growth conditions boosted CAD activity and itaconate titer about 10-fold to values of 1440mUmg<SUP>−1</SUP> and 30mM. Reduction of isocitrate dehydrogenase activity via exchange of the ATG start codon to GTG or TTG resulted in maximal itaconate titers of 60mM (7.8gl<SUP>−1</SUP>), a molar yield of 0.4molmol<SUP>−1</SUP>, and a volumetric productivity of 2.1mmoll<SUP>−1</SUP> h<SUP>−1</SUP>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>C. glutamicum</I> is highly tolerant to itaconate and does not metabolize it. </LI> <LI> Expression of <I>cis</I>-aconitate decarboxylase allowed itaconate formation from glucose. </LI> <LI> Fusion of the decarboxylase with maltose binding protein improved activity. </LI> <LI> Nitrogen-limitation boosted CAD activity and itaconate formation. </LI> <LI> Reduced isocitrate dehydrogenase activity enhanced itaconate formation. </LI> </UL> </P>