A Novel Rhodotorula evergladensis CXCN-6 Rich in Torularhodin and PUFAs with Potent Antioxidant and Anti-Inflammatory Activities.

Carotenoids and microbial lipids are valuable bioactive compounds with potent antioxidant and anti-inflammatory properties. Microbial biosynthesis provides a sustainable alternative to conventional plant extraction and chemical synthesis. Here, we report the isolation and characterization of a novel oleaginous yeast, Rhodotorula evergladensis CXCN-6, from the surface of Nymphaea 'Gorgeous Purple'. The strain displayed intense reddish-orange pigmentation due to intracellular carotenoid accumulation. HPLC and LC-MS analyses identified torularhodin as the predominant carotenoid (m/z 563.4 [M](+)), while lipids were rich in linoleic (C18:2), oleic (C18:1), and α-linolenic (C18:3) acids. Under optimized fermentation, CXCN-6 yielded 63.56 mg/L torularhodin and 9.83 g/L total lipids. The CXCN-6 extract showed strong DPPH and ABTS radical scavenging activities and significantly reduced intracellular ROS levels in UVA (9 J/cm(2))-stimulated HaCaT cells. It also suppressed IL-6 and TNF-α secretion in LPS-activated macrophages without cytotoxicity. Collectively, these results establish R. evergladensis CXCN-6 as a novel and efficient microbial platform for the co-production of torularhodin and PUFA-rich lipids with potent antioxidant and anti-inflammatory properties, offering promising applications in nutraceutical, skincare, and functional food industries.