Improved terephthalic acid production from p-xylene using metabolically engineered Pseudomonas putida

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• Terephthalic acid (TPA) is a key monomer for polyethylene terephthalate (PET) production.
• Current PET manufacturing relies on petrochemical processes, driving demand for sustainable alternatives.
• Biomanufacturing of TPA offers a greener approach to producing this essential chemical.

Purpose of the Study:

• To engineer Pseudomonas putida KT2440 for efficient biocatalytic conversion of p-xylene to TPA.
• To develop a cost-competitive, plasmid-free, antibiotic-free, and inducer-free TPA bioproduction process.
• To enhance TPA production through advanced metabolic engineering strategies.

Main Methods:

• Integrated heterologous genes into the P. putida KT2440 chromosome using RecET-based markerless recombineering.
• Utilized constitutive promoters for gene overexpression and integrated multiple gene copies into ribosomal RNA genes.
• Optimized a fed-batch fermentation process for enhanced TPA production.

Main Results:

• Engineered P. putida produced 38.25 ± 0.11 g/L of TPA from p-xylene.
• Achieved a high molar conversion yield of 99.6 ± 0.6%.
• Demonstrated a superior biotransformation process suitable for industrial scale-up.

Conclusions:

• Metabolic engineering of P. putida KT2440 enables efficient and sustainable TPA biomanufacturing.
• The developed process offers a viable alternative to conventional TPA production methods.
• This work supports the commercialization of bio-based TPA for the polymer industry.