A light-switchable bidirectional expression system in filamentous fungus Trichoderma reesei

Area of Science:

• Biotechnology
• Molecular Biology
• Industrial Microbiology

Background:

• Trichoderma reesei is a key fungus for industrial enzyme and protein production.
• Current methods for heterologous protein expression in T. reesei have limitations.
• Light-inducible systems offer precise transcriptional control in various organisms.

Purpose of the Study:

• To develop a novel light-inducible system for controlled gene expression in Trichoderma reesei.
• To engineer a cellulase-free T. reesei strain for improved heterologous protein production.
• To demonstrate simultaneous, on-off control of multiple gene expression using light.

Main Methods:

• Construction of light-inducible transactivators and bidirectional promoters.
• Development of a "light-on" and "light-off" promoter system.
• Gene knockout of xyr1, cbh1, and cbh2 to create a cellulase-free background.
• Testing of the system's efficiency and specificity under blue light.

Main Results:

• Successful construction of light-inducible transactivators and promoters in T. reesei.
• Creation of a functional on-off light-switchable system for simultaneous gene control.
• Achieved a native cellulase-free background with minimal background protein expression.
• Demonstrated significantly improved heterologous protein expression under blue light.

Conclusions:

• The developed light-switchable system provides unprecedented control over gene expression in T. reesei.
• This system enables simultaneous regulation of multiple genes, enhancing heterologous protein production.
• The cellulase-free background further optimizes protein expression, with broad industrial applications.