초록
<P><B>Abstract</B></P> <P>In this work, <I>Scheffersomyces stipitis</I>, the yeast with excellent xylose-utilizing ability, was firstly engineered for fumaric acid production from xylose with the heterologous reductive pathway from <I>Rhizopus oryzae</I> FM19, and 1.86g/L fumaric acid was produced by the initial strain PSRPMF under the oxygen-limited condition. Furthermore, three strategies were performed to improve the fumaric acid production, including increasing the reductive pathway activity by codon optimization, blocking the fumaric acid conversion in tricarboxylic acid cycle by knocking out the native fumarases, and improving the fumaric acid transportation by overexpressing heterologous transporter. Finally, the strain PSYPMFfS was obtained and the fumaric acid titer reached to 4.67g/L, significantly increased by 37.92-fold than that of the control strain PSPYSS. It was indicated that the <I>S. stipitis</I> was a promising platform for fumaric acid production from xylose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>S. stipitis</I> was firstly engineered to produce fumaric acid from xylose. </LI> <LI> Heterologous reductive pathway from <I>R. oryzae</I> was overexpressed. </LI> <LI> Codon optimization was efficient for improving the reductive pathway activity. </LI> <LI> Fumaric acid titer was improved by double-deletions of <I>Psfum1</I> and <I>Psfum2</I>. </LI> <LI> The overexpression of transporter YMAE1 was necessary for fumaric acid production. </LI> </UL> </P>