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Engineered Corynebacterium glutamicum as an endotoxin-free platform strain for lactate-based polyester production
Yuyang Song1, Ken'ichiro Matsumoto, Miwa Yamada
1Division of Biotechnology and Macromolecular Chemistry, Graduate School of Engineering, Hokkaido University, N13-W8, Kita-ku, Sapporo, 060-8628, Japan.
Applied Microbiology and Biotechnology
|December 1, 2011
Summary
Metabolically engineered Corynebacterium glutamicum produces high-purity lactate-based polyesters. This endotoxin-free platform offers a promising route for food-grade and biomedical poly(lactic acid)-like materials.
Area of Science:
- Biotechnology and Metabolic Engineering
- Polymer Science
- Microbial Fermentation
Background:
- Previous work established lactate (LA)-based polyester biosynthesis in Escherichia coli.
- A need exists for improved, endotoxin-free platforms for polyester production.
Purpose of the Study:
- To engineer Corynebacterium glutamicum for efficient production of lactate-based polyesters.
- To develop a practical, food-grade, and biomedical-applicable platform for poly(lactic acid)-like polymers.
Main Methods:
- Metabolic engineering of C. glutamicum to synthesize lactyl-CoA (LA-CoA) and 3-hydroxybutyryl-CoA (3HB-CoA).
- Utilized D:-lactate dehydrogenase, propionyl-CoA transferase, β-ketothiolase (PhaA), and NADPH-dependent acetoacetyl-CoA reductase (PhaB).
- Copolymerization catalyzed by the LA-polymerizing enzyme (LPE).
Main Results:
- Achieved production of P(LA-co-3HB) with high LA fractions (96.8 mol%).
- Further increased LA fraction to 99.3 mol% by omitting PhaA and PhaB.
- Demonstrated functional expression of designed metabolic pathways.
Conclusions:
- Engineered C. glutamicum serves as an effective endotoxin-free platform for lactate-based polyesters.
- The platform is suitable for producing food-grade and biomedically applicable poly(lactic acid)-like materials.
- Metabolic pathway optimization enhances polyester composition for specific applications.
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