Efficient Biosynthesis of Selenium-Enriched Saccharomyces cerevisiae via Siderophore-Assisted selenite uptake and...

Selenium (Se) is essential for health, but its common inorganic forms are toxic, limiting its direct dietary use. This study proposes a siderophore-assisted strategy for producing selenium-enriched Saccharomyces cerevisiae with improved efficiency. The siderophore produced by Aspergillus sp, isolated from iron-rich soil, significantly enhanced S. cerevisiae tolerance to sodium selenite (up to 2000 μg/mL) and increased intracellular Se content to 3.89 mg/g. X-ray Photoelectron Spectroscopy (XPS) and High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) analyses confirmed efficient biotransformation of Se (IV) to organic selenium, primarily selenomethionine (Se-Met), accounting for 97.85% of total selenoamino acids (1201.52 ng/g). The selenium-enriched S. cerevisiae showed potent antioxidant activity, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging rates of 59.85% and 97.18%, respectively. Transcriptomic analysis revealed that Siderophore-mediated selenium transport is not fully dependent on the high-affinity phosphate transporters and may involve the participation of Pho91p. This study offers a feasible strategy for producing selenium-enriched S. cerevisiae and a promising approach for bioavailable organic selenium supplements.