Green Enzymatic Synthesis of Succinic Acid

Succinic acid is an important petroleum-derived industrial chemical precursor for the synthesis of 1,4-butanediol, tetrahydrofuran, and polybutylene succinate (PBS). Polybutylene succinate is a green alternative to conventional plastics due to its biodegradable nature. A major challenge in using PBS is finding a sustainable non-petroleum source of succinic acid. Microbe-based bioreactors are faced with difficulties such as acidic conditions and the extraction of succinic acid from liquid culture. An enzyme-based bioreactor presents an appealing solution for the green biosynthesis of succinic acid. Succinate can be produced from an ethene-forming enzyme in genetically engineered E. coli. This research focuses on using a non-heme 2-oxoglutarate-dependent ethene-forming (EFE) enzyme for the enzymatic synthesis for succinate. An E. coli codon optimized gene was inserted into a PET15b vector. Specialized E. coli were then transformed for the expression and purification of the EFE protein. An enzymatic bioreactor containing the EFE protein was used to synthesize succinic acid. High performance liquid chromatography (HPLC) quantified the concentration of succinic acid over the course of the synthesis and recrystallization was used for succinic acid recovery and purification. This research investigates enzymatic synthesis as a sustainable and environmentally-friendly source of succinic acid