CMMMech
CMMMech > Element > Germanium

Germanium element Critical Material

Germanium (Ge), grounded by the neutral-atom ChEBI identifier. This element is distinct from the GeO2 reagent and dissolved germanium species used in the experiments, germanium-bearing minerals and coal wastes. The US 2025 list names the germanium commodity; its designation is mapped to this element without extending it to every germanium-bearing material.

Identifiers & Classification

System Identifier Label
CHEBI CHEBI:30441 germanium atom

Criticality Designations

Jurisdiction List Name Edition / Document Classification Source
United States of America USGS Final List of Critical Minerals 2025; Federal Register 90:50494-50497; published 7 November 2025 critical usgs2025

Microbial & Biochemical Mechanisms (1)

Catechol-associated germanium accumulation by Pseudomonas putida

other Microbial

Associated Organisms: Pseudomonas putida (NCBITaxon:303)

Living ATCC 33015 cells accumulated germanium from GeO2-supplemented laboratory media. Catechol-associated accumulation included an intracellular component alongside envelope binding. An inducible catechol-transport explanation remains proposed. The two papers are companion studies from the same laboratory, not independent replication. Bioaccumulation is represented as other rather than isolated-product recovery.

Experimental Context & Analytical Limits:
NCBITaxon:303 identifies the species, not ATCC 33015. The kinetic study used acetate-grown inocula, aerated mineral medium at pH 7.3, 2 mM GeO2, and 4 mM catechol or 5/10 mM acetate; cultivation used 30 degrees C and reciprocating shaking. Washed, sonicated pellets were measured by 71Ge scintillation, normalized to dry cell mass, over approximately 15 hours. The separate localization/fractionation study used 10 mM GeO2, 4 mM catechol or 10 mM acetate, and 30 degrees C shaking; its fractionation assay used 300 mL with about 0.15 g initial dry cells and 12 hours. Cells were washed with distilled water before sonication, differential centrifugation and radiometric fraction analysis.
Curated Evidence Points:
Pages 1100-1103 and Figures 1-4 report approximately 22 micromol Ge/g dry cells with catechol versus an approximately 10 micromol/g acetate plateau. Mixed substrates delayed the second accumulation phase. Medium germanium decreased only about 5%, despite catechol consumption; this is not efficient solution depletion or a recovery yield.
The kinetic association supports substrate-dependent uptake but does not identify a transporter experimentally. The methods report two separate 4 mL aliquots of each sonicated suspension for scintillation counting; biological-replicate counts, statistical uncertainty and matched killed-cell or cell-free controls are not reported. Surface binding also contributes to the pellet signal.
Table 1 reports 2.46 versus 0.81 mg Ge/g dry cells with catechol versus acetate, respectively, and 83.4% versus 58.0% of accumulated Ge in the soluble fraction. Figures 1-3 compare Ge-free controls with loaded cells: envelope contrast and catechol-associated cytoplasmic deposits support localization. The 10 mM assay is distinct from the companion 2 mM kinetic experiment.
Fractionation and microscopy support intracellular accumulation, but electron contrast does not identify a germanium mineral phase or oxidation state. Replication and uncertainty are not reported. Neither study establishes transporter causality, selective product isolation, a full mass balance or industrial deployment.

Sources & References

  1. chebi_germanium: ChEBI CHEBI:30441 — germanium atom; Ge, net charge zero
    https://www.ebi.ac.uk/chebi/CHEBI:30441 (accessed 2026-10-11)
  2. usgs2025: USGS (2025). Final 2025 List of Critical Minerals. Federal Register 90:50494-50497, document 2025-19813; Germanium row in final table.
    https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-11)
  3. ncbi_putida: NCBI Taxonomy 303 — Pseudomonas putida, species rank
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=303&mode=Info (accessed 2026-10-11)
  4. chmielowski1986: Chmielowski J and Kłapcińska B (1986). Bioaccumulation of Germanium by Pseudomonas putida in the Presence of Two Selected Substrates. Applied and Environmental Microbiology 51:1099-1103. doi:10.1128/aem.51.5.1099-1103.1986; methods and Figures 1-4.
    https://doi.org/10.1128/aem.51.5.1099-1103.1986 (accessed 2026-10-11)
  5. klapcinska1986: Kłapcińska B and Chmielowski J (1986). Binding of Germanium to Pseudomonas putida Cells. Applied and Environmental Microbiology 51:1144-1147. doi:10.1128/aem.51.5.1144-1147.1986; methods, Table 1 and Figures 1-3.
    https://doi.org/10.1128/aem.51.5.1144-1147.1986 (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T05:18:03Z Codex (GPT-6; Codex) record_creation Created the germanium element record with verified identity, dated US criticality and two companion microbial accumulation experiments. Preserved different assay concentrations, weak controls, low solution depletion and provisional transport interpretation. Independent scientific review is a separate subsequent artifact.
2026-10-11T05:22:59Z Codex (GPT-6; Codex) evidence_clarification Corrected independent review finding F1 in 20261011T052122Z-germanium-round5-independent, issue 30, by preserving the reported duplicate scintillation aliquots and specifying that biological-replicate counts and statistical uncertainty are unreported.

Record source: data/records/germanium.yaml