초록
<P>Lycopene plays an important role as an antioxidative and anticancer agent, and is an increasingly valuable commodity in the global market. <I>Rhodobacter sphaeroides</I>, a carotenogenic and phototrophic bacterium, is an efficient and practical host for carotenoid production. Herein, we explored the potential of metabolically engineered <I>Rb. sphaeroides</I> as a novel platform to produce lycopene. The basal lycopene-producing strain was generated by introducing an exogenous <I>crtI</I><SUB>4</SUB> from <I>Rhodospirillum rubrum</I> to replace the native <I>crtI</I><SUB>3</SUB> and deleting <I>crtC</I> in <I>Rb. sphaeroides.</I> Furthermore, knocking out <I>zwf</I> blocked the competitive pentose phosphate pathway and improved the lycopene content by 88%. Finally, the methylerythritol phosphate pathway was reinforced by integration of <I>dxs</I> combined with <I>zwf</I> deletion, which further increased the lycopene content. The final engineered strain produced lycopene to 10.32 mg/g dry cell weight. This study describes a new lycopene producer and provides insight into a photosynthetic bacterium as a host for lycopene biosynthesis.</P><BR>[FIG OMISSION]</BR>