Bifunctional optogenetic switch for improving shikimic acid production in E. coli

Area of Science:

• Synthetic biology
• Metabolic engineering
• Optogenetics

Background:

• Decoupling biomass formation and product synthesis enhances microbial production titers.
• Optogenetics offers light-inducible control of metabolic flux but is limited by available tools.
• Existing optogenetic tools require further development for broader applications.

Purpose of the Study:

• To expand the optogenetic toolkit by developing novel light-sensitive systems.
• To create a bifunctional optogenetic switch for orthogonal control of gene transcription and protein accumulation.
• To apply the developed switch for enhanced microbial production of value-added chemicals.

Main Methods:

• Reprogramming the TetR repressor and TEV protease to create two optogenetic systems (TPRS and TPAS).
• Merging TPRS and TPAS to construct a bifunctional optogenetic switch.
• Utilizing the switch to decouple biomass formation and shikimic acid biosynthesis in E. coli.

Main Results:

• Achieved a record titer of 35 g/L shikimic acid in minimal medium using E. coli.
• Further increased shikimic acid production to 76 g/L in rich medium.
• Demonstrated successful decoupling of biomass and product formation via light-controlled regulation.

Conclusions:

• The developed cost-effective, light-controlled switch provides a novel tool for metabolic pathway regulation.
• This approach offers environmentally friendly methods for microbial production.
• The optogenetic system is potentially applicable to the biosynthesis of various value-added chemicals.