Insights into the functionality and stability of designer cellulosomes at elevated temperatures

Area of Science:

• Biotechnology
• Biorefining
• Enzymology

Background:

• Enzymatic lignocellulose breakdown is crucial for second-generation biorefineries.
• Current cellulosome applications are limited to 50°C due to mesophilic enzyme origins.
• Designer cellulosomes enhance enzyme synergy via the proximity effect.

Purpose of the Study:

• To investigate the high-temperature functionality of designer cellulosomes using mesophilic scaffoldin components and thermophilic enzymes.
• To develop efficient cellulosome systems for elevated-temperature biorefinery processes.

Main Methods:

• Constructed a tetravalent scaffoldin with mesophilic and thermophilic cohesins/cellulose-binding modules.
• Combined scaffoldin with four thermophilic enzymes fused to specific dockerins.
• Assessed the stability and functionality of chimeric enzymes and cellulosome complexes at 60°C.
• Evaluated the hydrolysis efficiency of corn stover using the full designer cellulosome compared to free enzymes.

Main Results:

• Chimeric enzymes retained biochemical properties and thermal stability.
• Individual and full cellulosome complexes were stable and functional for at least 6 hours at 60°C.
• The designer cellulosome demonstrated over 50% higher efficiency in corn stover hydrolysis compared to free enzymes.

Conclusions:

• Scaffoldin components of mesophilic origin can function effectively at elevated temperatures.
• This study provides a framework for producing designer cellulosomes suitable for high-temperature biorefinery applications.
• The developed designer cellulosomes significantly improve lignocellulose hydrolysis efficiency.