Lead element Critical Material
Lead (Pb), represented as an element distinct from dissolved lead, pyromorphite mineral and lead-bearing commodities or wastes. Laboratory bacterial cultures enhanced Pb release from synthetic pyromorphite, demonstrating that microbial interactions can remobilize previously immobilized lead. The United States 2025 designation names the lead commodity; it does not designate every lead compound, mineral or secondary resource.
Identifiers & Classification
| System | Identifier | Label |
|---|---|---|
| CHEBI |
CHEBI:25016
|
lead 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)
Culture-enhanced lead release from synthetic pyromorphite
bioleaching
Microbial
Associated Organisms:
Pseudomonas putida (NCBITaxon:303)
Growing Pseudomonas putida IBPRS KKP 1136 cultures increased filtered-solution Pb relative to uninoculated controls during dissolution of synthetic pyromorphite. The effect was greater when the mineral was the only added phosphate source. Nutrient scavenging, metabolites and cell-associated binding are candidate contributors; the experiment does not identify a unique dissolution pathway. This laboratory remobilization observation is not an isolated-metal recovery process or proof of a field remediation outcome.
Experimental Context & Analytical Limits:
Topolska et al. E.II: 0.05 g synthetic pyromorphite in 100 mL medium in 500 mL flasks, run in triplicate for 305 h at 21 +/- 1 degrees Celsius and 100 rpm. XRD and SEM-EDS characterized the starting mineral; wet chemical analysis gave Pb5.09(PO4)2.96Cl. Mineral portions were heated at 180 degrees Celsius for 3 h before use. Mid-log cells grown to OD600 0.8 were pelleted, resuspended in the experimental solution and inoculated 1:100. The paper identifies the strain by earlier numerical taxonomy; the linked species identifier does not independently verify that strain assignment. MP+ contained 0.5 g/L K2HPO4, disodium succinate, glycerol, salts and FeEDTA; MP- omitted K2HPO4. The source reports FeEDTA as 30 mM, an unusual medium specification retained as reported rather than silently corrected. Initial pH was about 7.3; biotic pH rose toward 9, while abiotic pH stayed near its initial value. Controls included uninoculated mineral suspensions, growth without mineral and chlorapatite comparisons. ICP-MS measured total Pb and P after centrifugation and 0.2 micrometre polycarbonate filtration; a separate acid-digestion comparison assessed cell-associated Pb. Feed was a synthetic mineral, not a contaminated soil or industrial ore.
Topolska et al. E.II: 0.05 g synthetic pyromorphite in 100 mL medium in 500 mL flasks, run in triplicate for 305 h at 21 +/- 1 degrees Celsius and 100 rpm. XRD and SEM-EDS characterized the starting mineral; wet chemical analysis gave Pb5.09(PO4)2.96Cl. Mineral portions were heated at 180 degrees Celsius for 3 h before use. Mid-log cells grown to OD600 0.8 were pelleted, resuspended in the experimental solution and inoculated 1:100. The paper identifies the strain by earlier numerical taxonomy; the linked species identifier does not independently verify that strain assignment. MP+ contained 0.5 g/L K2HPO4, disodium succinate, glycerol, salts and FeEDTA; MP- omitted K2HPO4. The source reports FeEDTA as 30 mM, an unusual medium specification retained as reported rather than silently corrected. Initial pH was about 7.3; biotic pH rose toward 9, while abiotic pH stayed near its initial value. Controls included uninoculated mineral suspensions, growth without mineral and chlorapatite comparisons. ICP-MS measured total Pb and P after centrifugation and 0.2 micrometre polycarbonate filtration; a separate acid-digestion comparison assessed cell-associated Pb. Feed was a synthetic mineral, not a contaminated soil or industrial ore.
Curated Evidence Points:
Support
Source:
topolska_2014
Experimental methods, Table 2, Figure 4 and Table 3: after 305 h, filtered-solution Pb in MP- was 13.5 +/- 0.37 micromolar with bacteria versus 1.47 +/- 0.16 micromolar without; MP+ values were 3.66 +/- 0.31 and 1.15 +/- 0.07 micromolar, respectively. Errors are reported standard deviations of triplicates. These are solution concentrations, not extraction percentages or isolated-product yields. Figure 2 also shows limited growth when pyromorphite supplies phosphate, with no growth in the no-phosphate/no-mineral control.
Partial
Source:
topolska_2014
Solution analysis, cell-bound Pb method and Results E.II: the separate 100 h MP+ acid-digestion comparison assigned 13.6 +/- 0.4 micromolar Pb to cells, reported as 94% of total Pb released in that comparison. That fraction is not the 305 h filtered-solution result or a 94% mineral-recovery yield. Sorption could be reversible; no long-term permanence is demonstrated.
Partial
Source:
topolska_2014
Discussion, Microbially enhanced Pb remobilization: pH was not held equal across biotic and abiotic arms. The authors argue that the observed pH range is insufficient to explain the Pb difference but explicitly do not completely exclude its contribution. Unmeasured metabolites, P uptake and binding are proposed contributors; acidification, a named enzyme or a unique chelation mechanism is not established.
Context_only
Source:
kato_2022
Results 2.3 and Figures 6-7 report pyromorphite/hydrocerussite associated with a different isolate, Pseudomonas sp. KKY-29, exposed to lead acetate. This distinct deposition experiment does not contradict Topolska's dissolution result under different substrate and nutrient conditions, or establish permanent immobilization. Kato's Results 2.6 and Discussion reverse the phosphate-condition phase assignments, and biomass/phosphate units are inconsistent; those assignments, removal percentages and proposed phosphate-metabolism causality are not transferred here.
Sources & References
-
topolska_2014: Topolska, Latowski, Kaschabek, Manecki, Merkel and Rakovan (2014; online July 20, 2013). Pb remobilization by bacterially mediated dissolution of pyromorphite Pb5(PO4)3Cl in presence of phosphate-solubilizing Pseudomonas putida. Environmental Science and Pollution Research 21, 1079-1089. DOI 10.1007/s11356-013-1968-3; PMID 23872890; PMC3880484.
https://doi.org/10.1007/s11356-013-1968-3 (accessed 2026-10-11) -
kato_2022: Kato et al. (2022). Deposition of Lead Phosphate by Lead-Tolerant Bacteria Isolated from Fresh Water near an Abandoned Mine. International Journal of Molecular Sciences 23(5), 2483. DOI 10.3390/ijms23052483; PMID 35269625; PMC8910126. Distinct deposition context; quantitative conditions and phosphate-phase mapping remain inconsistent.
https://doi.org/10.3390/ijms23052483 (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; Lead row in the final commodity table. The adjacent No is the byproduct/co-product column, not criticality.
https://www.govinfo.gov/content/pkg/FR-2025-11-07/html/2025-19813.htm (accessed 2026-10-11) -
chebi_lead: ChEBI:25016 - lead atom; Pb, net charge zero
https://www.ebi.ac.uk/chebi/CHEBI:25016 (accessed 2026-10-11) -
ncbi_putida: NCBI Taxonomy 303: Pseudomonas putida, species. This identifier does not resolve IBPRS KKP 1136 at strain level.
https://api.ncbi.nlm.nih.gov/datasets/v2/taxonomy/taxon/303/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 lead, the named US 2025 designation and controlled pyromorphite remobilization; preserved cell-associated versus filtered-solution Pb, unequal pH, reported medium uncertainty and distinct deposition context. |
Record source: data/records/lead.yaml