Cystofilobasidium ferigula co-production of lipids and carotenoids using crude glycerol

This research optimized culture conditions to enhance the concurrent synthesis of lipids and carotenoids by Cystofilobasidium ferigula CCMA 1623 using crude glycerol as a low-cost substrate. Despite limited biotechnological studies on this yeast, a response surface methodology with a central composite design was applied to examine the influence of yeast extract levels, temperature, and aeration. Gas chromatography–mass spectrometry (GC–MS) identified a fatty acid profile predominantly composed of stearic, palmitic, oleic (omega-9), and linoleic (omega-6) acids similar to vegetable oils. Raman spectroscopy was employed as a rapid, non-destructive analytical tool to detect molecular signatures consistent with lipid and carotenoid-type compounds in the biomass, providing complementary structural evidence to support compositional and functional analyses. The carotenoid extract exhibited notable antioxidant activity as determined by the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic) acid radical scavenging assay (ABTS), the ferric reducing antioxidant power assay (FRAP), and the 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay (DPPH). Under optimized conditions, the cell extract showed 52.89 ± 2.55% lipid content (1.57 ± 0.25 g/L) and 107.6 ± 2.4 µg/g total carotenoids, supporting its potential as a sustainable platform for the biotechnological production of high-value metabolites.