Metabolic Engineering and Process Intensification for Muconic Acid Production Using Saccharomyces cerevisiae.

Area of Science:

• Biotechnology and metabolic engineering
• Sustainable chemistry and bioprocessing
• Industrial microbiology

Background:

• Biobased organic acids are key for a sustainable economy.
• Muconic acid is a versatile platform chemical for adipic and terephthalic acids.
• Efficient microbial production of muconic acid requires strain improvement and optimized processes.

Purpose of the Study:

• Engineer *Saccharomyces cerevisiae* for enhanced muconic acid production.
• Eliminate C2 dependency and improve product tolerance.
• Integrate fed-batch fermentation with *in situ* product recovery (ISPR).

Main Methods:

• Genetic engineering of *Saccharomyces cerevisiae* by reintroducing *PDC5* and overexpressing *QDR3*.
• Low-pH fed-batch fermentation at bioreactor scale.
• Integrated *in situ* product recovery using a biocompatible organic phase (CYTOP 503 and canola oil).

Main Results:

• Achieved a 300% increase in muconic acid titer (9.3 g/L) and 185% increase in peak productivity (0.100 g/L/h) with ISPR.
• Significantly reduced protocatechuic acid byproduct formation.
• Alleviated product inhibition through continuous extraction, improving overall performance.

Conclusions:

• The engineered yeast strain and ISPR process enable efficient, high-titer muconic acid production.
• This approach advances the sustainable production of biobased chemicals.
• Metabolic engineering combined with advanced bioprocessing is crucial for industrial viability.