Optogenetic control of Corynebacterium glutamicum gene expression

Area of Science:

• Synthetic Biology
• Metabolic Engineering
• Microbial Biotechnology

Background:

• Corynebacterium glutamicum is a vital industrial microorganism for producing valuable chemicals and amino acids.
• Efficient production relies on balancing metabolic flux between cellular growth and product synthesis.
• Current gene regulation tools for C. glutamicum lack dynamic control and are often toxic, hindering advanced metabolic engineering strategies.

Purpose of the Study:

• To develop novel, dynamic, and minimally toxic gene regulation tools for Corynebacterium glutamicum using optogenetics.
• To establish a light-controlled gene expression and interference system for precise metabolic pathway regulation.
• To engineer C. glutamicum for the biosynthesis of chitin oligosaccharides (CHOSs) and chondroitin sulphate oligosaccharides A (CSA).

Main Methods:

• Development of 'LightOnC.glu', a light-controlled RNA-binding protein (RBP) system for transcription factor construction.
• Implementation of a CRISPR/Cpf1-based system for high-performance light-controlled gene interference.
• Design and construction of a light-controlled bioreactor for optimizing oligosaccharide production.

Main Results:

• Successful establishment of the first light-controlled gene expression and interference systems in Corynebacterium glutamicum.
• Demonstrated de novo production of CHOSs and CSA in C. glutamicum.
• Achieved a record CHOSs production concentration of 6.2 g/L in a light-controlled bioreactor.

Conclusions:

• A programmable, light-responsive genetic circuit was established in C. glutamicum, advancing dynamic regulation theory.
• The developed optogenetic tools offer a broadly applicable platform for metabolic engineering in C. glutamicum and other microbial hosts.
• This work paves the way for enhanced biosynthesis of complex compounds through precise, light-mediated metabolic control.