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Cadmium element Critical Material

Cadmium (Cd), atomic number 48. The neutral-atom identifier grounds the element, not Cd(II), cadmium chloride, cadmium sulfide, or a mineral species. India's June 2023 committee list names the cadmium material; that dated designation is mapped to this element without extending it to its compounds. This is the 30-material committee assessment, not a claim about the separate statutory critical/strategic schedule or current law. Curated laboratory evidence concerns culture-associated cadmium-sulfide formation.

Identifiers & Classification

System Identifier Label
CHEBI CHEBI:22977 cadmium atom

Criticality Designations

Jurisdiction List Name Edition / Document Classification Source
India Ministry of Mines committee list of 30 Critical Minerals for India June 2023 committee report; launched 28 June 2023 critical india_committee_2023

Microbial & Biochemical Mechanisms (1)

Culture-associated cadmium-sulfide formation

biomineralization Microbial

Associated Organisms: Klebsiella planticola (NCBITaxon:575)

Living Klebsiella planticola Cd-1 cultures formed CdS-associated solids. This supports laboratory immobilization, not elemental-cadmium reduction, purified-product recovery or industrial deployment.

Experimental Context & Analytical Limits:
Anaerobic synthetic CdCl2 medium used pyruvate/glucose and Trizma buffer, initially around pH 7.1. Washed, freeze-dried late-stationary biomass from 5 mM Cd(II) cultures was characterized spectroscopically. A separate thiosulfate-amended assay used 5 mM Cd(II) and 5 or 10 mM thiosulfate. Exact precipitation incubation temperature, elapsed harvest time and vessel volume are not explicit. NCBITaxon:575 identifies the published species, not a verified Cd-1 strain accession.
Curated Evidence Points:
Figures 2-3 compare sulfur XANES and cadmium EXAFS against reference compounds and cadmium-free biomass, supporting Cd-S coordination; Cd-O ligands also remain unresolved. The separate washed-pellet methylene-blue assay estimates approximately 1 mM CdS from sulfide, not directly measured cadmium recovery.
No matched cell-free precipitation comparison is reported. Thiosulfate interferes with the sulfide assay and was removed by pellet washing. These experiments do not identify an enzyme, establish a complete cadmium mass balance, or distinguish all abiotic contributions.

Sources & References

  1. chebi_cadmium: ChEBI CHEBI:22977 — cadmium atom
    https://www.ebi.ac.uk/chebi/CHEBI:22977 (accessed 2026-10-11)
  2. india_committee_2023: Government of India, Ministry of Mines (June 2023). Critical Minerals for India: Report of the Committee on Identification of Critical Minerals. Chapter 9, printed page 32 / PDF page 40, item 4 Cadmium; summary on PDF page 11.
    https://mines.gov.in/admin/storage/app/uploads/649d4212cceb01688027666.pdf (accessed 2026-10-11)
  3. india_launch_2023: Ministry of Mines / Press Information Bureau (28 June 2023). Union Minister Pralhad Joshi unveils List of Critical Minerals for India. Release 1936083; launch of the 30-material expert-committee report.
    https://www.pib.gov.in/PressReleaseIframePage.aspx?PRID=1936083&lang=2&reg=48 (accessed 2026-10-11)
  4. sharma_2000: Sharma PK, Balkwill DL, Frenkel A and Vairavamurthy MA (2000). A New Klebsiella planticola Strain (Cd-1) Grows Anaerobically at High Cadmium Concentrations and Precipitates Cadmium Sulfide. Applied and Environmental Microbiology 66:3083-3087. doi:10.1128/AEM.66.7.3083-3087.2000. Growth-medium and transformation sections; Figures 2-3; sulfide measurement subsection.
    https://doi.org/10.1128/AEM.66.7.3083-3087.2000 (accessed 2026-10-11)
  5. taxonomy_planticola: NCBI Taxonomy 575 — Klebsiella planticola, species rank; Raoultella planticola listed as a homotypic synonym.
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=575&mode=Info (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T04:34:43Z codex (GPT-6) CREATE Added cadmium identity and India's dated committee-list designation, with primary Cd-1 precipitation evidence, spectroscopy and assay limits, unresolved controls, and explicit laboratory scope.

Record source: data/records/cadmium.yaml