Exploring the lipids, carotenoids, and vitamins content of Rhodotorula glutinis with selenium supplementation under lipid accumulating and growth proliferation conditions

• Published in: BMC microbiology 2024-11, Vol.24 (1), p.451-13, Article 451
• Main Authors: Elfeky, Nora, Rizk, Aya, Gharieb, Mohamed M
• Format: Article
• Language: English
• Subjects: Accumulation; Amino acids; Autophagy; Basidiomycota; Biodegradation; Biomass; Carotenoids; Carotenoids - metabolism; Cartenoids; Cell walls; Chemical properties; Culture media; Culture Media - chemistry; Detoxification; Dietary supplements; Environmental degradation; Fatty acid composition; Fatty acids; Fatty Acids - metabolism; Gas chromatography; Genetic resources; Growth; Growth media; Gypsum; High performance liquid chromatography; Intracellular; Investigations; Linoleic acid; Lipid bodies; Lipid Metabolism - drug effects; Lipids; Lipids - analysis; Lipids - biosynthesis; Lipogenesis; Liquid chromatography; Microbiological research; Microbiological synthesis; Monounsaturated fatty acids; Oleic acid; Organelles; Palmitic acid; Physiological aspects; Poultry feed; Production processes; Rhodotorula - drug effects; Rhodotorula - growth & development; Rhodotorula - metabolism; Rhodotorula glutinis; Saturated fatty acids; Selenites; Selenium; Selenium - metabolism; Selenium - pharmacology; Selenium compounds; Sodium; Sodium compounds; Sodium selenite; Sodium Selenite - metabolism; Sodium Selenite - pharmacology; Synthesis; Transmission electron microscope; Transmission electron microscopes; Transmission electron microscopy; Vitamins; Vitamins - metabolism; Vitamins - pharmacology; Yeast; Yeasts
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-024-03585-x

Rhodotorula glutinis, a specific type of yeast, has been recognised as a superior resource for generating selenium-enriched biomass that possesses exceptional nutritional and functional attributes. The purpose of this investigation was to assess the effect of sodium selenite at different concentrations on lipid and carotenoid synthesis, as well as the growth of R. glutinis. The lipid's fatty acid composition was determined using gas chromatography (GC). The vitamins were detected by high-performance liquid chromatography (HPLC). Transmission electron microscopy was used to detect the structural modification of yeast cells caused by the addition of sodium selenite to the growth medium, as well as the accumulation of elemental selenium in the yeast cells. The yeast cells demonstrated the ability to endure high concentrations of sodium selenite under lipid accumulation (LAM) and growth-promoting (YPD) conditions. 25.0 mM and 30.0 mM, respectively, were published as the IC50 values for the LAM and YPD conditions. In both growth media, 1 mM sodium selenite boosted lipid synthesis. Lipid accumulation increased 26% in LAM to 11.4 g/l and 18% in YPD to 4.3 g/l. Adding 1 mM and 3 mM sodium selenite to YPD medium increased total and cellular carotenoids by 22.8% (646.7 µg/L and 32.12 µg/g) and 48.7% (783.3 µg/L and 36.43 µg/g), respectively. Palmitic acid was identified as the most abundant fatty acid in all treatments, followed by oleic acid and linoleic acid. The concentrations of water soluble vitamins (WSV) and fat soluble vitamins (FSV) were generally significantly increased after supplementation with 1.0 mM sodium selenite. TEM examination revealed a significant reduction in lipid bodies accumulation in the yeast cells when sodium selenite was added to lipid-promoting environments. This decline is accompanied by an augmentation in the formation of peroxisomes, indicating that selenium has a direct impact on the degradation of fatty acids. In addition, autophagy appears to be the primary mechanism by which selenium ions are detoxified. Additionally, intracellular organelles disintegrate, cytoplasmic vacuolization occurs, and the cell wall and plasma membrane rupture, resulting in the discharge of cytoplasmic contents, when a high concentration of sodium selenite (20.0 mM) is added. Also, the presence of numerous electron-dense granules suggests an intracellular selenium-detoxification pathway. This study proposes the use of YPD with 1 mM sodium selenite to cult