Fig. 1
From: Development and optimization of a microbial co-culture system for heterologous indigo biosynthesis
Design of E. coli–E. coli co-culture system for indigo biosynthesis. The pathway intermediate tryptophan was provided by the upstream strain, and the conversion of tryptophan to indigo was performed by downstream strain. Biosensor-assisted selection circuit was introduced to the upstream strain for enhancing the tryptophan provision. gTME selection was introduced into the downstream strain for improving the indigo production. Blue arrows represent the over-expressed genes