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Immobilization of Multi-biocatalysts in Alginate Beads for Cofactor Regeneration and Improved Reusability
Published on: April 22, 2016
Continuous asymmetric ketone reduction processes with recombinant Escherichia coli
Kirsten Schroer1, Ursula Mackfeld, Ivy Ai Wei Tan
1Institut für Biotechnologie 2, Forschungszentrum Jülich, 52425 Jülich, Germany.
Journal of Biotechnology
|September 11, 2007
Summary
Recombinant Escherichia coli efficiently reduced methyl acetoacetate using alcohol dehydrogenase. Substrate-coupled cofactor regeneration enabled a 7-week biotransformation with high substrate concentrations and biocatalyst stability.
Area of Science:
- Biocatalysis and metabolic engineering
- Enzyme technology
- Industrial microbiology
Background:
- Methyl acetoacetate reduction is crucial for synthesizing valuable chemicals.
- Recombinant Escherichia coli offers a scalable platform for biocatalysis.
- Efficient cofactor regeneration is essential for continuous biotransformation processes.
Purpose of the Study:
- To evaluate different cofactor regeneration strategies for methyl acetoacetate reduction using recombinant Escherichia coli.
- To assess the stability and performance of the biocatalyst under high substrate concentrations.
Main Methods:
- Continuous biotransformation using recombinant Escherichia coli expressing Lactobacillus brevis alcohol dehydrogenase.
- Comparison of three cofactor regeneration approaches: enzyme-coupled (formate dehydrogenase, glucose dehydrogenase) and substrate-coupled (2-propanol oxidation).
- Analysis of biocatalyst stability and cofactor leakage under extended operation and high substrate loads.
Main Results:
- Enzyme-coupled regeneration resulted in rapid biocatalyst deactivation.
- Substrate-coupled regeneration using 2-propanol allowed continuous operation for 7 weeks.
- High substrate (2.5 mol L-1) and cosubstrate (2.8 mol L-1) concentrations were tolerated.
- The biocatalyst demonstrated good stability with minimal cofactor leakage even under extreme conditions.
Conclusions:
- Substrate-coupled cofactor regeneration is superior for long-term, high-load methyl acetoacetate biotransformation.
- Recombinant Escherichia coli with alcohol dehydrogenase is a robust biocatalyst for industrial applications.
- This approach offers a stable and efficient method for producing valuable chemicals.
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