Expression of Weimberg xylose utilization pathway for succinate production by cyanobacteria under diurnal condition

Background: Succinate is a widely used platform chemical in plastics and food industries. While autotrophic succinate producing cyanobacteria has previously been demonstrated, a major limitation to its practical utilization is the lack of continuous production at night. Methods: Here we showcase a constant succinate production in diurnal condition by additionally introducing a xylose utilization pathway (XUP) into succinate producing strain. This implemented pathway enables the strain to convert xylose into α-ketoglutarate which then becomes succinate. Significant Findings: The engineered stain produced succinate with the productivity of 2.4 mg/L/hr under dark condition with xylose supplemented. Additionally, two-fold increase of succinate titer at constant light condition compare to base strain. Together this work showed the installation of xylose utilization system in cyanobacteria is a feasible strategy to provide carbon flux to α-ketoglutarate, which may also be applicable for increasing the production of other TCA cycle derived compounds.