Abstract
Epoxy resins are high-performance materials extensively utilized in construction and protective coatings, playing a vital role in enhancing durability and sustainability by extending the service life of structures such as aircraft, automobiles, and offshore equipment. Despite their benefits, conventional epoxy resins raise environmental and health concerns due to their reliance on fossil-derived components and potentially hazardous chemical makeup (1). To address these issues, the NordiCoats project aims to develop an innovative class of epoxy resins derived from renewable microbial oils and biopolymers. The oleaginous yeast Rhodotorula toruloides was selected as a promising microbial production platform due to its notable ability to accumulate single-cell oils. In this study we optimized fed-batch approach for Rhodotorula toruloides fermentation using glucose and yeast extract, The optimization was performed in 3 L laboratory-scale bioreactors, and the most efficient fed-batch approach was subsequently scaled up in a 100 L pilot bioreactor. The fed-batch process achieved a biomass concentration of 35 g/L, with lipids comprising 51% of the dry cell weight. The resulting biomass was harvested for downstream lipid extraction and conversion into sustainable epoxy coatings. From 4.5 kg of freeze-dried biomass (containing 1.56 kg total lipids), 678 g of oil was obtained (43% extraction yield). By optimizing fermentation and extraction conditions, the NordiCoats project demonstrates the feasibility of scaling up microbial-derived oils for epoxy resin production. These findings pave the way for future research to refine process parameters and support a sustainable, bio-based production pipeline for high-performance coating materials.