Abstract
Lipids, carotenoids, and β-carotene are produced by Rhodotorula mucilaginosa. Further optimization experiments were carried out by analyzing the substrate utilization of yeast medium supplemented with different sources of carbon, nitrogen, phosphate, and sodium acetate. Additional screening was carried out in batch shake flasks to examine the effects of various nitrogen sources, phosphate concentrations, and sodium acetate. Notably, when sodium acetate was supplied as an additional carbon source in the medium, remarkable improvements in the production of key compounds were seen, such as the highest yield of cell dry weight (CDW) was 1.65 ± 0.94 gL⁻¹, with a lipid output of 66.53% (w/w), showing a substantial quantity of lipid accumulation in comparison to the biomass. The lipid concentration was 2.48 ± 1.03 gL⁻¹. Furthermore, 5.84 ± 0.05 µg g⁻¹ of β-carotene and 37.66 ± 2.13 µg g⁻¹ of carotenoids were produced. The following were observed in batch reactor fed with sodium acetate 5.02 ± 0.83 gL⁻¹ for cell dry weight (CDW); 3.30 ± 0.27 gL⁻¹ for lipid concentration; 65.73 ± 0.81% (w/w) for lipid content; 40.33 ± 1.84 µg g⁻¹ for carotenoid synthesis; and 17.63 ± 0.32 µg g⁻¹ for β-carotene production. Fed-batch bioreactor using sodium acetate, R. mucilaginosa produced significant levels of biomass, lipids, and carotenoids, including β-carotene 48.36 ± 1.14 µg g⁻¹ of carotenoids, 21.38 ± 1.14 µg g⁻¹ of β-carotene, a lipid concentration of 4.06 ± 0.17 gL⁻¹, and a lipid content of 68.58 ± 1.95%.