An L-Trp biosensor was developed based on native control of the tnaCAB operon.
Deoxyviolacein pathway was divided into two parts, connected by an intermediate.
The senor was used for screening upstream module library based on enhanced output.
Screening downstream enzyme mutant library was based on reduced sensor output
With this push/pull approach, 1.92g/L deoxyviolacein titer was obtained.