The global dominance of fossil-fuel-based plastics has led to severe environmental pollution, prompting a shift toward biodegradable alternatives like polylactic acid (PLA). However, current PLA production relies heavily on agricultural resources such as corn and sugarcane to produce the monomer, lactic acid (LA). This dependence on crops raises sustainability concerns. To address this, a research team has successfully engineered E. coli to synthesize PLA directly from solar C₂ chemicals, specifically ethanol and acetate, which can be generated from CO₂ through artificial photosynthesis.
In this study, the researchers constructed a synthetic metabolic pathway in E. coli that converts ethanol and acetate into PLA. A key breakthrough was the discovery that cofeeding ethanol and acetate synergistically enhances production. The PLA titer achieved under cofeeding conditions was 5-fold and 53-fold higher than that obtained with ethanol or acetate alone, respectively.
Proteomics and metabolomics analyses revealed that this synergistic effect upregulates the glyoxylate shunt, the Entner-Doudoroff pathway, and serine anabolism. These metabolic adjustments facilitate the efficient generation of lactic acid from acetyl-CoA. By integrating this optimized biological pathway with a CO₂ electroreduction unit, the team achieved a complete “CO₂-to-PLA” conversion process, which offers a sustainable alternative to traditional manufacturing, potentially reducing the environmental footprint of plastic production.
The work entitled “Synthesis of polylactic acid from solar C₂ chemicals in engineered Escherichia coli” was published on Systems Microbiology and Biomanufacturing (published on April 9, 2026).
DOI：10.1007/s43393-026-00446-8