초록
<P><B>Abstract</B></P> <P> <I>Yarrowia lipolytica</I> is a biotechnological chassis for the production of a range of products, such as microbial oils and organic acids. However, it is unable to consume xylose, the major pentose in lignocellulosic hydrolysates, which are considered a preferred carbon source for bioprocesses due to their low cost, wide abundance and high sugar content.</P> <P>Here, we engineered <I>Y. lipolytica</I> to metabolize xylose to produce lipids or citric acid. The overexpression of xylose reductase and xylitol dehydrogenase from <I>Scheffersomyces stipitis</I> were necessary but not sufficient to permit growth. The additional overexpression of the endogenous xylulokinase enabled identical growth as the wild type strain in glucose. This mutant was able to produce up to 80g/L of citric acid from xylose. Transferring these modifications to a lipid-overproducing strain boosted the production of lipids from xylose. This is the first step towards a consolidated bioprocess to produce chemicals and fuels from lignocellulosic materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The overexpressions of heterologous XR and XDH and endogenous XK allow good growth in xylose. </LI> <LI> Further engineered strains boosted lipid accumulation in xylose as sole carbon source. </LI> <LI> Bioreactor experiments with xylose and glycerol as co-substrates produced 50g/L of lipids. </LI> <LI> Bioreactor experiments in specific conditions produced 80g/L of citric acid from xylose. </LI> </UL> </P>