Metabolic design of a platform Escherichia coli strain producing various chorismate derivatives

A synthetic metabolic pathway suitable for the production of chorismate derivatives was designed in Escherichia coil. An L-phenylalanine-overproducing E. coil strain was engineered to enhance the availability of phosphoenolpyruvate (PEP), which is a key precursor in the biosynthesis of aromatic compounds in microbes. Two major reactions converting PEP to pyruvate were inactivated. Using this modified E.coli as a base strain, we tested our system by carrying out the production of salicylate, a highdemand aromatic chemical. The titer of salicylate reached 11.5 g/L in batch culture after 48 h cultivation in a 2-liter jar fermentor, and the yield from glucose as the sole carbon source exceeded 40% (mol/mol). In this test case, we found that pyruvate was synthesized primarily via salicylate formation and the reaction converting oxaloacetate to pyruvate. In order to demonstrate the generality of our designed strain, we employed this platform for the production of each of 7 different chorismate derivatives. Each of these industrially important chemicals was successfully produced to levels of 1-3 g/L in test tube-scale culture. (C) 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.