Oleaginous yeasts as a sustainable alternative source of lipids: an investigation into microbial isolation from food sources, fermentation kinetics, fatty acid profiles, and potential health benefits of microbial lipids

Oleaginous yeasts present a promising sustainable source of lipids, also known as single cell oils (SCOs), offering an alternative to traditional oils with potential applications in food industries. In this study, some oleaginous yeast strains, which were isolated from sugarcane bagasse, salted whole anchovies, and pickled mustard greens, were genetically identified as Kodamaea ohmeri , Rhodotorula mucilaginosa , Candida tropicalis , Pichia kudriavzevii , and Zygosaccharomyces rouxii . To investigate the SCOs productivity of these strains, YPD broth was used and compared with low-nitrogen lipid-stimulating medium (LSM) which was enriched with numerous minerals as growth factors. The findings showed that LSM significantly enhanced the production of biomass and SCOs, exhibiting increases of 20.1–40.1% for biomass and 18.5–111.9% for SCOs. Among these strains, R. mucilaginosa exhibited the most proficient biosynthesis of SCOs, achieving a lipid yield of 7.67 g/L in LSM medium, in contrast to the other strains, which yielded between 1.57 and 2.63 g/L, with K. ohmeri following at 4.44 g/L. Accordingly, R. mucilaginosa biomass showed highest lipid accumulation, with values of 531.97 and 301.73 mg lipid/g of dry cell weight recorded for LSM and YPD, respectively. Regarding fatty acid profiles, linoleic acid (C18:2n6C), oleic acid (C18:1n9C), and palmitic acid (C16:0) were the predominant fatty acids identified in the SCOs of five yeast strains and there was a substantially higher contents of linoleic acid (46.92–49.11%) found in SCOs from R. mucilaginosa . Moreover, low atherogenic index, low thrombogenic index, and high hypo-/hyper-cholesterolemic ratio indicate the health benefits of SCOs from oleaginous yeasts as a sustainable alternative lipid source. • Five potential oleaginous yeasts were isolated from different food sources. • Rhodotorula mucilaginosa and Kodamaea ohmeri showed the highest biomass production. • R. mucilaginosa exhibited the highest lipid yield and accumulation (53.2%). • Higher linoleic acid content (46.92–49.11%) was found in oil from R. mucilaginosa. • Low atherogenic and thrombogenic indices imply oil’s potent cardiovascular benefit.