Engineering Acinetobacter baylyi ADP1 for mevalonate production from lignin-derived aromatic compounds

Area of Science:

• Biotechnology
• Synthetic Biology
• Microbial Engineering

Background:

• Lignin valorization is challenging due to its complex, heterogeneous structure.
• Biological processing offers a sustainable alternative to chemical methods for lignin conversion.
• Existing microbial platforms struggle with lignin-derived compounds, limiting their application.

Purpose of the Study:

• To engineer *Acinetobacter baylyi* ADP1 for the production of mevalonate from lignin-derived aromatics.
• To overcome limitations of traditional engineered organisms in lignin bioconversion.
• To establish a foundation for improved mevalonate production from renewable resources.

Main Methods:

• Engineered *Acinetobacter baylyi* ADP1 to express the mevalonate pathway.
• Validated pathway activity using various lignin-derived aromatic substrates.
• Optimized mevalonate production through gene knockout (wax ester synthesis) and fed-batch cultivation.

Main Results:

• Successfully expressed and validated the mevalonate pathway in *A. baylyi* ADP1.
• Demonstrated production of mevalonate from multiple lignin-derived aromatic compounds.
• Achieved a 7.5-fold improvement in mevalonate titers, reaching 1014 mg/L (6.8 mM) through strain and process optimization.

Conclusions:

• *Acinetobacter baylyi* ADP1 is a viable host for producing mevalonate from lignin.
• Metabolic engineering and process optimization significantly enhance mevalonate yields.
• This work provides a robust platform for future development of lignin-based bioproducts.