Carbon as a Simple Support for Redox Biocatalysis in Continuous Flow

Area of Science:

• Biocatalysis and Enzyme Engineering
• Chemical Reactor Design
• Sustainable Chemistry

Background:

• NADH-dependent biocatalysis often requires efficient cofactor regeneration systems.
• Continuous flow reactors offer advantages in process control and scalability for enzymatic reactions.
• Enzyme immobilization is crucial for enzyme reusability and reactor stability.

Purpose of the Study:

• To optimize a continuous packed bed reactor for NADH-dependent biocatalysis.
• To achieve high conversion rates and yields using co-immobilized enzymes.
• To evaluate the reactor's stability and efficiency for pyruvate to lactate conversion.

Main Methods:

• Co-immobilization of lactate dehydrogenase and formate dehydrogenase on a carbon support.
• Optimization of a continuous packed bed reactor configuration.
• In situ cofactor recycling using formate dehydrogenase.
• Monitoring of conversion, E-factors, and space-time yields.

Main Results:

• 100% conversion achieved within a 30-minute residence time.
• Low E-factors ranging from 2.5 to 11.
• Space-time yields up to 22.9 g L^-1 h^-1.
• Sustained full conversion for over 30 hours of continuous operation.

Conclusions:

• The optimized continuous packed bed reactor is highly efficient for NADH-dependent biocatalysis.
• Co-immobilization and in situ cofactor recycling enable robust and stable enzymatic processes.
• This system presents a promising approach for sustainable chemical production.