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Response-Surface-Optimized and Scaled-Up Microbial Electrosynthesis of Chiral Alcohols
Jeannine C Mayr1,2, Luis F M Rosa3, Natalia Klinger1
1Institute of Biochemical Engineering, Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany.
Chemsuschem
|January 18, 2020
Summary
Genetically engineered Escherichia coli efficiently produce chiral alcohols via microbial electrosynthesis (MES). This optimized bioelectrosynthesis process achieved high yield and enantioselectivity, paving the way for broader biotechnological applications.
Area of Science:
- Biotechnology
- Synthetic Biology
- Electrochemistry
Background:
- Escherichia coli is a versatile host for expressing enzymes via plasmids, making it suitable for bioelectrosynthesis.
- Microbial electrosynthesis (MES) enables the production of chiral alcohols using genetically modified microorganisms.
Purpose of the Study:
- To optimize the microbial electrosynthesis of (R)-1-phenylethanol from acetophenone using engineered Escherichia coli.
- To assess the efficiency and scalability of this bioelectrosynthetic process.
Main Methods:
- Utilized genetically modified E. coli overexpressing NADPH-dependent alcohol dehydrogenase from Lactobacillus brevis.
- Employed methyl viologen as a mediator for electron transfer in the electrosynthesis process.
- Applied a design of experiment (DoE) approach for process optimization and scaled up using electrobioreactors.
Main Results:
- Achieved a 2.4-fold increased yield (94±7%) and a 3.9-fold increased reaction rate (324±67 μm h⁻¹).
- Reached a coulombic efficiency of up to 68±7% with >99% enantioselectivity for (R)-1-phenylethanol.
- Scaled up to 1 L, achieving a titer of 12.8±2.0 mm under batch and fed-batch conditions.
Conclusions:
- Optimized MES process in E. coli demonstrates high efficiency and enantioselectivity for chiral alcohol production.
- The developed system is scalable and adaptable for standard biotechnological processes.
- E. coli shows potential as a universal chassis for microbial electrosynthesis applications.
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