Directed evolution of a cellobiose utilization pathway in Saccharomyces cerevisiae by simultaneously engineering...

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Biotechnology

Background:

• Efficient biofuel and specialty chemical production relies on optimizing metabolic pathways.
• Cellobiose utilization is a key pathway for biomass conversion.
• This study focuses on engineering the cellobiose utilization pathway.

Purpose of the Study:

• To optimize cellobiose consumption and ethanol productivity.
• To engineer both beta-glucosidase (gh1-1) and cellodextrin transporter (cdt-1) proteins simultaneously.
• To demonstrate pathway engineering through directed evolution.

Main Methods:

• Simultaneous engineering of gh1-1 and cdt-1 proteins.
• Directed evolution for pathway optimization.
• Assessment of strain growth rate and metabolite analysis.

Main Results:

• A 47% increase in strain-specific growth rate on cellobiose.
• A 49% increase in cellobiose consumption rate.
• A 64% increase in ethanol productivity.

Conclusions:

• Simultaneous engineering of multiple pathway proteins enhances cellobiose utilization in S. cerevisiae.
• This approach is broadly applicable to other metabolic pathways with appropriate screening.
• Improved in vivo cellobiose utilization can reduce biomass pretreatment costs for biofuel production.