Pathway Engineering for Phenethylamine Production in Escherichia coli

In this study, the metabolic pathway of phenethylamine synthesis was reconstructed by chromosomal integration and overexpression of the Enterococcus faecium pdc gene encoding phenylalanine decarboxylase in Escherichia coli. The genes encoding 3-deoxy-d-arabinoheptulosonate-7-phosphate synthase (aroG), shikimate kinase II (aroL), chorismate mutase/prephenate dehydratase (pheA), and tyrosine aminotransferase (tyrB) in the phenethylamine synthetic pathway were sequentially chromosomally overexpressed. The phosphotransferase system was replaced by deleting the ptsH-ptsI-crr genes and chromosomally overexpressing the genes encoding galactose permease (galP) and glucokinase (glk). In addition, the zwf gene encoding glucose-6-phosphate dehydrogenase in the pentose phosphate pathway was chromosomally overexpressed, generating the final engineered E. coli strain AUD9. The AUD9 strain produced 2.65 g L^-1 phenethylamine with a yield of 0.27 g of phenethylamine g^-1 glucose in batch fermentation; fed-batch fermentation of AUD9 produced 38.82 g L^-1 phenethylamine with a productivity of 1.08 g L^-1 h^-1 phenethylamine, demonstrating its potential for industrial fermentative production of phenethylamine.