Bio-based production of chemicals from renewable resources is becoming increasingly important for sustainable chemical industry. In this study, Escherichia coli was metabolically engineered to produce 1,3-diaminopropane (1,3-DAP), a monomer for engineering plastics. Comparing heterologous C4 and C5 pathways for 1,3-DAP production by genome-scale in silico flux analysis revealed that the C4 pathway employing Acinetobacter baumannii dat and ddc genes, encoding 2-ketoglutarate 4-aminotransferase and L-2,4-diaminobutanoate decarboxylase, respectively, was the more efficient pathway. In a strain that has feedback resistant aspartokinases, the ppc and aspC genes were overexpressed to increase flux towards 1,3-DAP synthesis. Also, studies on 128 synthetic small RNAs applied in gene knock-down revealed that knocking out pfkA increases 1,3-DAP production. Overexpression of ppc and aspC genes in the pfkA deleted strain resulted in production titers of 1.39 and 1.35 g l-1 of 1,3-DAP, respectively. Fed-batch fermentation of the final engineered E. coli strain allowed production of 13 g l-1 of 1,3-DAP in a glucose minimal medium.
Bibliographical noteFunding Information:
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries from the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF) of Korea (NRF-2012-C1AAA001-2012M1A2A2026556).