Work

Acetate co-feeding increases ethylene glycol assimilation and glycolic acid production in Yarrowia lipolytica

Year: 2025

Type: article

Abstract: Upcycling ethylene glycol (EG) and terephthalic acid (TPA) — key monomers derived from the depolymerisation of polyethylene terephthalate (PET) — is a promising strategy for advancing the circular economy of plastics. This study investigates the metabolic fate of EG and its conversion into glycolic acid (GA) by the non-conventional yeast Yarrowia lipolytica. While EG alone does not support growth in a minimal medium, the addition of acetate (Ac) significantly enhances EG assimilation and GA production. 13C labelling experiments and metabolic flux analysis revealed that a small but measurable fraction of EG-derived carbon is incorporated into biomass via glycine and serine biosynthesis and the glyoxylate cycle when acetate is supplied as a carbon source. Ac-EG co-feeding resulted in the production of 48.41 ± 1.4 g/L of GA after 66 hours, corresponding to a molar yield of 73% and a productivity of 0.73 g/(L x h). These results highlight the potential of Y. lipolytica as a microbial platform for EG valorisation and contribute to sustainable strategies for the bioconversion of plastic waste.

Source: Bioresource Technology

DOI: 10.1016/j.biortech.2025.133540