Closing the CO2-to-glycolic acid loop through efficient methanol bioconversion enabled by cofactor-neutral metabolic rewiring.

Chemo-biological valorization of CO2 into value-added chemicals, such as the biodegradable plastic monomer glycolic acid (GA), represents a promising frontier in sustainable manufacturing. However, the realization of this synergistic loop is hindered by the low carbon efficiency of C1 bioconversion. Herein, we address this challenge by engineering an efficient methanol bioconversion platform that selectively upgrades CO2-derived methanol into GA. To address metabolic redox constraints inherent to methanol assimilation that severely limit carbon yield, we reprogrammed Komagataella phaffii by constructing a cofactor-neutral biosynthetic route that couples NADPH generation directly to GA formation. Combined with the elimination of competing carbon sinks, this design eradicates the redox constraints that typically limit C1 assimilation. As a result, carbon flux toward GA surged by 4.6-fold while maintaining cellular fitness. Translating this rewired module to a 5-L bioreactor establishes a benchmark, achieving a titer of 41.2 g/L and the highest reported yield of 0.41 g/g for methanol-only bioconversion. Life-cycle assessment (LCA) reveals a 59.0% lower global warming potential (GWP) relative to fossil-based routes. This study establishes a high-efficiency methanol bioconversion platform for GA production, completing the CO2-to-GA loop and providing a sustainable route for the utilization of CO2-derived carbon resources.