Lipid Metabolism Optimisation in Ashbya gossypii to Produce Microbial Oils From Xylose-Rich Feedstocks

Abstract

The development of lipogenic biocatalysts with enhanced ability for agro-waste bioconversion represents a critical challenge in microbial biotechnology, requiring the metabolic optimisation of different oil-producing microorganisms. Ashbya gossypii, although not classified as an oleaginous microorganism, exhibits a significant capacity for intracellular lipid accumulation and can efficiently metabolise various low-cost substrates, including xylose-rich feedstocks. Indeed, previous works have shown metabolically engineered strains of A. gossypii reaching between 20% and 40% of the cell dry weight in lipid content when using xylose as the primary carbon source. Building on these findings, this study employs a multigenic optimisation strategy to further enhance lipid production by increasing the lipogenic supply of both acetyl-CoA and NADPH, while simultaneously abolishing β-oxidation, in a strain engineered for efficient xylose utilisation. The optimised strain achieved approximately 60% lipid content when cultivated on mixed sugar formulations designed to simulate xylose-rich feedstocks. These results underscore the potential of A. gossypii as a promising microbial platform for sustainable lipid production from renewable resources, reinforcing its utility in biotechnological applications for bio-based chemical and biofuel production.