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Carbon dioxide (CO 2 ) is an abundant and cheap carbon source that is partly responsible for global warming in the atmosphere. The objective of this study was to construct a recombinant E. coli strain that can show enhanced production of succinate derived from CO 2 . In this study, we confirmed the enhancement of utilization by analyzing succinate containing one carbon-13 ( 13 C) derived from 13 CO 2 . Firstly, the carbonic anhydrase gene (SP(-)HCCA) derived from Hahella chejuensis KCTC 2396 was over-expressed to enhance carbon flux toward bicarbonate ion (HCO 3 ) synthesis in E. coli. The phosphoenolpyruvate carboxylase gene (ppc) was over-expressed to enhance the production of oxaloacetate by enhancing the carbon flux. Compared with the control strain, the percentage of the succinate containing one - ) synthesis in E. coli. The phosphoenolpyruvate carboxylase gene (ppc) was over-expressed to enhance the production of oxaloacetate by enhancing the carbon flux. Compared with the control strain, the percentage of the succinate containing one 13 C (succinate 119 ) to total succinate was enhanced by approximately 2.80-fold and the amount of succinate 119 also increased by approximately 4.09-fold in SGJS120. Secondly, the lactate dehydrogenase gene (ldhA) was deleted to re-direct the utilization of the carbon source from glucose to enhance succinate production in SGJS120. However, ldhA deletion did not increase CO 2 utilization in SJGS120. Finally, the phosphotransferase system gene (ptsG) and pyruvate kinase F gene (pykF) were deleted to increase the amount of phosphoenolpyruvate (PEP). SGJS126 (pykF deletion strain) showed the highest increase, which was 6.05-fold higher than the control strain. From the results, SP(-)HCCA overexpression and pykF deletion may be useful for enhancing CO 2 utilization in E. coli. Additionally, engineered strains showed the potential to reduce the cost of succinate production by using an industrially cheaper carbon source such as CO 2 and converting CO 2 to a valuable chemical., (Copyright © 2016. Published by Elsevier B.V.)

In this study, phosphoenolpyruvate carboxylase (PEPC) derived from Oceanimonas smirnovii (OS) was expressed as a soluble protein in Escherichia coli BL21(DE3). We isolated OS-PEPC (a recombinant PEPC protein) by his-tag purification. The purified protein showed a single band upon analysis with SDS-PAGE, and it had an apparent molecular mass of 98 kDa. Pufied OS-PEPC showed a specific activity value of 21.8 ± 0.495 U/mg protein. Especially, OS-PEPC showed the enzymatic activity between 40 and 50 °C. It maintained enzymatic activity in basic pH conditions (pH value, 9-10). We also measured OS-PEPC PEP and HCO3 (-) saturation kinetics and confirmed the effect of divalent cation on OS-PEPC activity.