Carotenoids production by Rhodosporidium paludigenum yeasts: Characterization of chemical composition, antioxidant and antimicrobial properties

Abstract

The high market potential imposed by natural carotenoids has turned the scientific interest in search for new strains, capable of synthesizing a wide spectrum of these pigments. In this study, Rhodosporidium paludigenum NCYC 2663 and 2664 were investigated for carotenoids production and lipid accumulation utilizing different carbon sources (glucose, fructose, sucrose, mixture of glucose: galactose). Strain R. paludigenum 2663 produced the highest total carotenoids titer (2.21 mg/L) when cultivated on sucrose, together with 4 g/L lipids (30% w/w content) and 7 g/L exopolysaccharides. In the case of R. paludigenum 2664, glucose favored the production of 2.93 mg/L total carotenoids and 1.57 g/L lipids (31.8% w/w content). Analysis of the chemical profile during fermentation revealed that β-carotene was the prominent carotenoid. Strain 2663 co-produced γ-carotene, torulene and torularhodin in lower amounts, whereas 2664 synthesized almost exclusively β-carotene. The produced lipids from strain 2663 were rich in oleic acid, while the presence of linoleic acid was also detected in the lipoic fraction from strain 2664. The obtained carotenoid extracts exhibited antioxidant (IC50 0.14 mg/mL) and high antimicrobial activity, against common bacterial and fungal pathogenic strains. The results of this study are promising for the utilization of biotechnologically produced carotenoids in food applications.