Bismuth element Critical Material
Bismuth (Bi), represented as an element distinct from bismuth subsalicylate, dissolved bismuth and intracellular Bi-bearing material. A laboratory Fusarium isolate accumulated Bi while growing on bismuth subsalicylate. The accumulated material was associated with phosphorus-rich granules, without an identified mineral phase or established Bi oxidation-state change. The United States 2025 designation names the bismuth commodity and does not automatically apply to every compound or resource.
Identifiers & Classification
| System | Identifier | Label |
|---|---|---|
| CHEBI |
CHEBI:33301
|
bismuth atom |
Criticality Designations
| Jurisdiction | List Name | Edition / Document | Classification | Source |
|---|---|---|---|---|
| United States of America | U.S. Department of the Interior Final List of Critical Minerals | 2025 (published November 7, 2025; 90 FR 50494-50497) | critical |
usgs_2025
|
Microbial & Biochemical Mechanisms (1)
Bismuth accumulation associated with Fusarium BI phosphorus-rich granules
other
Microbial
Associated Organisms:
Fusarium sp. BI (NCBITaxon:292829)
Fusarium sp. strain BI grew on bismuth subsalicylate and decreased the filtered soluble-Bi pool relative to an uninoculated suspension. TEM-EDS located Bi in intracellular phosphorus-rich granules, and polyphosphate-containing extracts also contained Bi. These observations support bioaccumulation with a proposed polyphosphate association; they do not identify crystalline bismuth phosphate, demonstrate Bi(III) reduction or establish the molecular transport route. No isolated-product recovery yield or industrial deployment was demonstrated.
Experimental Context & Analytical Limits:
Dodge and Wackett isolated Fusarium sp. BI from activated sewage sludge by enrichment on bismuth subsalicylate. Morphology and partial gene sequences supported an unresolved Fusarium isolate, not a named species. For soluble-Bi analysis, 1.5 mM bismuth subsalicylate suspensions in 250 mL minimal medium were preincubated on a shaker at 30 degrees Celsius for 24 h. Experimental flasks then received 100 microlitres of a 48 h culture grown on 1.5 mM salicylate. The medium contained 15 mM potassium phosphate buffer at pH 7.0, mineral salts and vitamins. Daily samples from inoculated and uninoculated flasks passed through 0.2 micrometre polyethersulfone filters; acidified filtrates were analyzed for total Bi by ICP-OES with an yttrium internal standard. Replicate number and error estimates for this time course are not specified. Separate TEM-EDS preparations used washed 96 h biomass grown on 1.5 mM bismuth subsalicylate or salicylate. Polyphosphate fractionation used 0.4 g wet biomass from 72 h cultures; Figure 4 reports three replicates, without establishing independent culture replication. Defined laboratory reagent suspensions are not ore, waste leachate or a recovery installation.
Dodge and Wackett isolated Fusarium sp. BI from activated sewage sludge by enrichment on bismuth subsalicylate. Morphology and partial gene sequences supported an unresolved Fusarium isolate, not a named species. For soluble-Bi analysis, 1.5 mM bismuth subsalicylate suspensions in 250 mL minimal medium were preincubated on a shaker at 30 degrees Celsius for 24 h. Experimental flasks then received 100 microlitres of a 48 h culture grown on 1.5 mM salicylate. The medium contained 15 mM potassium phosphate buffer at pH 7.0, mineral salts and vitamins. Daily samples from inoculated and uninoculated flasks passed through 0.2 micrometre polyethersulfone filters; acidified filtrates were analyzed for total Bi by ICP-OES with an yttrium internal standard. Replicate number and error estimates for this time course are not specified. Separate TEM-EDS preparations used washed 96 h biomass grown on 1.5 mM bismuth subsalicylate or salicylate. Polyphosphate fractionation used 0.4 g wet biomass from 72 h cultures; Figure 4 reports three replicates, without establishing independent culture replication. Defined laboratory reagent suspensions are not ore, waste leachate or a recovery installation.
Curated Evidence Points:
Support
Source:
dodge_2005
Methods, Assay for total soluble bismuth; Results, Depletion of bismuth; Figure 2: after 6 days the inoculated soluble-Bi pool decreased by approximately 0.4 mg/L, whereas the uninoculated control rose by approximately 0.2 mg/L. The source describes the decline as about 75% of initial soluble Bi. This denominator is the small filtered dissolved pool, not the total 1.5 mM bismuth-subsalicylate suspension, and no whole-feed mass balance or recovery percentage follows.
Support
Source:
dodge_2005
Methods, Electron microscopy and elemental analysis; Results, Localization; Figure 3: TEM-EDS of 60 nm sections found Bi with P and other elements in cytoplasmic/vacuolar granules. Salicylate-grown controls also had granules but no detected Bi. The EDS spot exceeded granule diameter; adjacent material contributes to the spectrum. Extracellular Bi-rich regions were also observed and interpreted as undissolved feed. Localization does not establish a unique chemical phase.
Partial
Source:
dodge_2005
Methods, Polyphosphate extraction and analysis; Results, Polyphosphate isolation; Figure 4: long-chain-soluble and granular fractions from Bi-fed biomass contained more Bi relative to phosphate than short-chain fractions and salicylate controls. Polyphosphate was measured as orthophosphate after hydrolysis. Co-fractionation and EDS support the proposed association but do not directly establish a Bi-polyphosphate molecular structure or show that polyphosphate causes tolerance.
Partial
Source:
dodge_2005
Results, Depletion of bismuth and Degradation of the salicylate moiety; Table 1: Bi oxidation states were not resolved. Salicylate hydroxylase and catechol 1,2-dioxygenase assays in crude extracts support an organic-substrate catabolic pathway, not a Bi reductase. The paper extends the salicylate pathway to bismuth subsalicylate by inference. Separate glucose/bismuth-nitrate tolerance assays and equivalent endpoint growth on salicylate and bismuth subsalicylate do not prove quantitative Bi recovery; growth on the Bi compound reached stationary phase about 24 h later.
Sources & References
-
dodge_2005: Dodge and Wackett (2005). Metabolism of Bismuth Subsalicylate and Intracellular Accumulation of Bismuth by Fusarium sp. Strain BI. Applied and Environmental Microbiology 71(2), 876-882. DOI 10.1128/AEM.71.2.876-882.2005; PMID 15691943; PMC546758.
https://doi.org/10.1128/AEM.71.2.876-882.2005 (accessed 2026-10-11) -
usgs_2025: U.S. Geological Survey (2025). Final 2025 List of Critical Minerals. Federal Register 90 FR 50494-50497, November 7, 2025; Bismuth row in the final commodity table.
https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-11) -
chebi_bismuth: ChEBI:33301 - bismuth atom; Bi, net charge zero
https://www.ebi.ac.uk/chebi/CHEBI:33301 (accessed 2026-10-11) -
ena_bi: ENA/INSDC AY725264.1: Fusarium sp. BI partial 18S rRNA sequence; sewage-sludge enrichment on bismuth subsalicylate, taxon 292829 and linked Dodge and Wackett publication.
https://www.ebi.ac.uk/ena/browser/view/AY725264.1 (accessed 2026-10-11) -
ncbi_bi: NCBI Taxonomy 292829: Fusarium sp. BI. Current informal isolate name, not a resolved named Fusarium species.
https://api.ncbi.nlm.nih.gov/datasets/v2/taxonomy/taxon/292829/dataset_report (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T06:24:33Z |
Codex (GPT-6; Codex) | create_record | Curated elemental bismuth, the US 2025 designation and exact Fusarium BI evidence, retaining soluble-pool denominators, analytical replication limits and unresolved phase/redox/transport mechanisms. Kept inaccessible nanocrystal studies in research. |
Record source: data/records/bismuth.yaml