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Production of Succinic Acid from Amino Acids in Escherichia coli.

Glutamate (Glu) and aspartate (Asp) are the most abundant amino acids in various sources of protein waste, recognized as a sustainable resource. In this study, Escherichia coli was engineered to produce succinic acid (SA) from Glu and Asp. Succinate dehydrogenase involved in the tricarboxylic acid was inactivated in the Glu-utilizing strain. To grow on Asp, this mutant strain was subjected to metabolic evolution. One resulting strain capable of metabolizing Asp was further evolved to improve the growth of Glu and Asp. After the deletion of arcA, the resulting strain was employed for the aerobic production of SA. The shake-flask culture was conducted with the minimal medium containing 10 g/L Glu and 10 g/L Asp. Finally, it resulted in the SA production, with a titer, the molar yield, and productivity reaching 72.8 mM (i.e., 8.6 g/L), 0.54 (ca. 75.4% of the theoretical yield), and 0.66 g/L/h, respectively. Overall, this study opens up a new avenue of the biorefinery platform based on renewable amino acids.