Engineered Escherichia coli for simultaneous utilization of galactose and glucose

In this study, the Leloir pathway of galactose metabolism was rebuilt in Escherichia coli to remove CCR and amplify galactose utilization rate. All genes encoding pathway enzymes were expressed under the control of a synthetic module that included promoters, 5'-untranslated regions, and terminators as a re-organized single operon in the chromosome. The engineered strain showed both an enhanced galactose utilization rate and the capacity to simultaneously assimilate galactose and glucose. This work demonstrates the feasibility of using synthetic biology tools to re-build biological systems for engineering purpose.