Environmental Valorization of Food Waste Through Lipid Production by Oleaginous Yeasts

Oleaginous yeasts are capable of accumulating intracellular lipids exceeding 20% of their dry cell weight, making them promising candidates for sustainable biofuel production. Lipomyces starkeyi , Metschnikowia pulcherrima , and Yarrowia lipolytica , three common oleaginous yeasts, were grown on detoxified food waste hydrolysate (DFWH) to assess their ability to grow and accumulate lipids. As a nutrient‐rich and low‐cost medium, DFWH effectively supported food waste valorization and microbial lipid synthesis. Single‐factor experiments systematically assessed the influence of key environmental parameters, including pH, temperature, carbon‐to‐nitrogen (C/N) ratio, and inoculum concentration, to identify favorable conditions for lipid production. L. starkeyi among the tested strains showed the highest lipid yield at 14.3 g/L, biomass yield at 7.3 g/L, and lipid content 51.05% performing best at pH 5, 25°C, and a C/N ratio of 80% and 10% inoculum concentration. Oleaginous yeasts accumulate triacylglycerol under nitrogen limitation and environmental stress, resulting in metabolic shifts. The findings overall show DFWH is an effective substrate for enhancing lipid biosynthesis in oleaginous microorganisms supporting its potential application in cost‐effective waste‐to‐biofuel bioprocesses. Single‐factor optimization illuminates strain behavior, yet statistical optimization paired with thorough lipid profiling will better establish DFWH‐based single‐cell oil production's industrial viability.