Phospholipids (PLs) are a class of lipids with many proven biological functions. They are commonly used in lipid replacement therapy to enrich cell membranes damaged in chronic neurodegenerative diseases, cancer, or aging processes. Due to their amphipathic nature, PLs have been widely used in food, cosmetic, and pharmaceutical products as natural emulsifiers and components of liposomes. In Yarrowia lipolytica, PLs are synthesized through a similar pathway like in higher eukaryotes. However, PL biosynthesis in this yeast is still poorly understood. The key intermediate in this pathway is phosphatidic acid, which in Y. lipolytica is mostly directed to the production of triacylglycerols and, in a lower amount, to PL. This study aimed to deliver a strain with improved PL production, with a particular emphasis on increased biosynthesis of phosphatidylcholine (PC). Several genetic modifications were performed: overexpression of genes from PL biosynthesis pathways as well as the deletion of genes responsible for PL degradation. The best performing strain (overexpressing CDP-diacylglycerol synthase (CDS) and phospholipid methyltransferase (OPI3)) reached 360% of PL improvement compared to the wild-type strain in glucose-based medium. With the substitution of glucose by glycerol, a preferred carbon source by Y. lipolytica, an almost 280% improvement of PL was obtained by transformant overexpressing CDS, OPI3, diacylglycerol kinase (DGK1), and glycerol kinase (GUT1) in comparison to the wild-type strain. To further increase the amount of PL, the optimization of culture conditions, followed by the upscaling to a 2 L bioreactor, were performed. Crude glycerol, being a cheap and renewable substrate, was used to reduce the costs of PL production. In this process 653.7 mg/L of PL, including 352.6 mg/L of PC, was obtained. This study proved that Y. lipolytica is an excellent potential producer of phospholipids, especially from waste substrates.

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 labeling 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 48.4 ± 1.4 g/L of GA after 66 h, corresponding to a molar yield of 73 % and a productivity of 0.73 g/(L·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.

Invertases are important enzymes used in the food industry. Despite many studies on the invertase-encoding SUC2 gene expression in the industrial yeast Yarrowia lipolytica, no biochemical characteristics of this enzyme expressed as heterologous protein have been provided. Here, two isoforms of extracellular invertase produced by Y. lipolytica were detected using ion-exchange chromatography. Specific activities of 226.45 and 432.66 U/mg for the first and second isoform, respectively, were determined. Basic characteristics of this enzyme were similar to the one isolated from Saccharomyces cerevisiae (optimum pH and temperature, metal ions inhibition, substrate specificity and fructooligosaccharides (FOS) biosynthesis). The apparent differences were higher K_M for sucrose (67 mM) and lower molecular mass (66 kDa) resulting from lower N-glycosylation level (9.1% of mass). The N-glycan structures determined by MALDI-TOF and HPLC represented high mannose structures, though with much shorter chains than hypermannosylated glycans from S. cerevisiae. Furthermore, galactose was detected as the modifying sugar in the glycan structures of invertase expressed in Y. lipolytica. N-glycans did not affect invertase activity but were important for its oligomerization. The expressed enzyme aggregated into dimers, tetramers, hexamers, and octamers, as well as structures of higher molecular mass, which might be decamers, which have not been described so far in the literature.

Lycopene, a natural carotenoid with antioxidant and health-promoting properties, has attracted attention as a valuable compound for the food, pharmaceutical, and cosmetic industries. Conventional production methods based on plant extraction or chemical synthesis are limited by low yields, high costs, and environmental concerns. In this study, the oleaginous yeast Yarrowia lipolytica was engineered as an alternative microbial cell factory for sustainable lycopene biosynthesis using short-chain fatty acids (SCFAs)—such as acetate, butyrate, and propionate—as inexpensive, renewable carbon sources. Four heterologous genes from Pantoea agglomerans (crtI, crtB, crtE, and idi) were codon-optimized and integrated into the Y. lipolytica genome using different expression systems, including the Golden Gate Assembly strategy. Among the tested strains, PS05/4lyc/GGA, characterized by enhanced phospholipid biosynthesis, demonstrated the highest lycopene yield of 462.9 mg/g dry cell weight and a titer of 3.41 g/L on butyrate medium—values comparable to or exceeding those reported for bioreactor-scale fermentations. The results indicate that co-activation of phospholipid and carotenoid biosynthesis pathways creates favorable intracellular conditions for hydrophobic pigment accumulation. Moreover, the use of SCFAs improved acetyl-CoA availability and redirected carbon flux through the mevalonate pathway, enhancing productivity. Strains with elevated membrane lipid biosynthesis also exhibited higher metabolic stability and stress tolerance.

Tretinoin (all-trans-retinoic acid, ATRA) is an established therapy for acute promyelocytic leukemia (APL) and neuroblastoma (NB); however, its broader oncological application is limited by poor bioavailability and rapid resistance development. In this study, we developed lipidic ester derivatives of ATRA as a potential prodrug approach aimed at modulating its physicochemical and biological properties. Three ATRA derivatives were evaluated in vitro in six human cancer cell lines: leukemia (MV4-11), gastric (AGS), colon (HT-29), lung (A549), and breast cancer cells (MCF-7, MDA-MB-468). Cytotoxicity toward normal human breast epithelial cells (MCF-10A) was also assessed. Among the synthesized derivatives, cetyl all-trans-retinoate (ATRA-CA) exhibited the strongest anticancer activity, showing up to threefold greater potency than ATRA, with inhibitory concentrations ranging from 1.34 to 23.1 µM and minimal toxicity toward normal cells. Moreover, ATRA-CA enhanced the efficacy of conventional chemotherapeutics. In A549 cells, treatment with 5 and 10 µM ATRA-CA reduced the cisplatin IC₅₀ from 25.7 ± 3.2 µM to 9.1 ± 3.0 and 5.9 ± 1.5 µM, corresponding to synergistic (CI = 0.63) and additive (CI = 0.88) effects, respectively. Similar effects were observed in MCF-7 cells and in combination with doxorubicin and paclitaxel.