Metabolic engineering of Escherichia coli for the production of 1,3-diaminopropane, a three carbon diamine

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.