Yttrium element Critical Material

Yttrium association with washed Galdieria ACUF 427 biomass

Experimental Context & Analytical Limits:
ACUF 427 originated from acidic soil in Gunnuhver, Iceland, and was obtained from the University of Naples algal collection. The 2022 source calls it G. sulphuraria; a 2025 primary study calls ACUF 427 G. daedala. The record therefore uses the verified genus identifier and retains the exact strain designation, without assigning the former species identifier to a newly named taxon. Cultures were prepared in Allen medium, pelleted and washed twice before exposure. Living biomass at an initial optical density of 5 at 550 nm was incubated in 2 mL water-plus-metal solutions in 24-well plates, with tilting agitation, at 37 degrees C for 24 h. Chloride salts supplied nominally 178 micromol/L of Y alone or each of Y, Ce, Eu and Tb in a mixture. The four initial pH values were 2.5, 3.5, 4.5 and 5.5, adjusted using sulfuric acid. The methods specify acid adjustment, although the abstract calls the solutions buffered. Metal-only and biomass-only controls were included; initial metal concentrations were checked by ICP-MS. Experiments were performed in triplicate, with mean and standard deviation reported. After exposure, supernatant and biomass were separated; the supernatant was filtered at 0.2 micrometres, and biomass was washed twice with water at the exposure pH before acid digestion and ICP-MS. Reported micromol/g values derive from the analyzed biomass fraction and its dry-mass denominator. They are not pure-metal yields. No resolved intracellular localization, desorption product or industrial operation is demonstrated.

Curated Evidence Points: