Hematite mineral
Hematite is the Fe2O3 mineral species listed as approved (A), with 1971 special-procedure status, in the IMA-CNMNC September 2026 master list. It is distinct from iron element, iron-ore commodities, other Fe2O3 polymorphs and mixed iron-bearing feeds. The experimental author-designated hematite below has substantial non-Fe oxide components; its bulk Fe2O3 percentage is not a quantified hematite phase abundance. No constituent criticality designation is inherited.
Microbial & Biochemical Mechanisms (1)
PMA2-2 culture-associated iron mobilization from a hematite feed
bioleaching
Microbial
Associated Organisms:
Priestia megaterium (NCBITaxon:1404)
PMA2-2 cultures produced higher filtered Fe concentrations than uninoculated hematite-feed controls during a short laboratory assay. Culture acidification accompanied this mobilization; the individual chemical and cellular contributions remain unresolved.
Experimental Context & Analytical Limits:
Living Priestia megaterium PMA2-2, isolated from Dracaena cochinchinensis rhizosphere soil in Purple Mountain, Nanjing, China, was precultured in LB for 12 hours at 37 degrees C and 160 rpm, harvested, washed and resuspended in 0.85% NaCl. The other-mineral assays followed the dissolution protocol: triplicate 220 mL flasks with 60 mL sterilized glucose minimal medium, 0.60 g of 75-150 micrometre mineral feed and 0.2 mL of 10^8 cells/mL suspension, incubated at 37 degrees C and 160 rpm, with separate flasks for 12- and 24-hour endpoints. Medium preparation pH was 7.0; its stated composition was 0.015% MgSO4.7H2O, 0.05% Na2HPO4.2H2O, 0.025% (NH4)2SO4, 0.01% KNO3 and 0.5% glucose. Element measurements used ICP-OES after centrifugation and 0.45 micrometre polyethersulfone filtration of a 10 mL aliquot; these are operationally filtered total-element concentrations, without oxidation-state resolution. Feed origin, cleaning procedure and quantitative phase analysis were not specified in the inspected methods and supplement. Table S7 reports 86.58% Fe2O3 and 9.82% SiO2, with other minor oxides, for the hematite feed. The organism is linked to GenBank CM125967.1; the paper's duplicated accession in its first Methods paragraph is not used to identify the comparator strain.
Living Priestia megaterium PMA2-2, isolated from Dracaena cochinchinensis rhizosphere soil in Purple Mountain, Nanjing, China, was precultured in LB for 12 hours at 37 degrees C and 160 rpm, harvested, washed and resuspended in 0.85% NaCl. The other-mineral assays followed the dissolution protocol: triplicate 220 mL flasks with 60 mL sterilized glucose minimal medium, 0.60 g of 75-150 micrometre mineral feed and 0.2 mL of 10^8 cells/mL suspension, incubated at 37 degrees C and 160 rpm, with separate flasks for 12- and 24-hour endpoints. Medium preparation pH was 7.0; its stated composition was 0.015% MgSO4.7H2O, 0.05% Na2HPO4.2H2O, 0.025% (NH4)2SO4, 0.01% KNO3 and 0.5% glucose. Element measurements used ICP-OES after centrifugation and 0.45 micrometre polyethersulfone filtration of a 10 mL aliquot; these are operationally filtered total-element concentrations, without oxidation-state resolution. Feed origin, cleaning procedure and quantitative phase analysis were not specified in the inspected methods and supplement. Table S7 reports 86.58% Fe2O3 and 9.82% SiO2, with other minor oxides, for the hematite feed. The organism is linked to GenBank CM125967.1; the paper's duplicated accession in its first Methods paragraph is not used to identify the comparator strain.
Curated Evidence Points:
Support
Source:
dong_2026
Supplement Table S6 (p11; mean +/- SD, n=3) reports filtered Fe of 25.95 +/- 0.90 and 71.43 +/- 1.56 micromol/L at 12 and 24 hours with PMA2-2, versus 0.04 +/- 0.00 micromol/L at both uninoculated endpoints. Culture pH was 4.69 +/- 0.05 and 4.66 +/- 0.06, versus control pH 7.16 +/- 0.04 and 7.12 +/- 0.05. These values support culture-associated mobilization from the stated impure feed; the rounded control SD is not proof of analytical exactness.
Partial
Source:
dong_2026
Uninoculated feed controls establish the conditional culture-associated difference, but no pH-matched or killed-cell hematite/feldspar comparator separates acidification from other effects. The acid-buffer comparison, detailed transcriptomics, metabolomics, EPS and biofilm assays concern biotite; their quantitative or causal results are not transferred to this feed. Figure 5 reports a separate 12-hour RT-qPCR response to this mineral; expression associations do not demonstrate gene necessity, and the Discussion explicitly calls for functional validation. No isolated-metal product, whole-feed recovery percentage, mineral-specific mass balance or industrial deployment is demonstrated.
Sources & References
-
ima_2026_09: IMA-CNMNC master list, September 2026, PDF p92 Hematite row and explanatory status definitions; retained official PDF reinspected 11 October 2026. The entry 1971 s.p. is special-procedure history, not an asserted external identifier.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-11) -
dong_2026: Dong, Zhang, Yu, Sheng, He and Sheng (2026). Genomic traits, transcriptional responses, and metabolic activities determine functional divergence in mineral dissolution between Priestia megaterium PMA2-2 and Priestia flexa PMD1-1. Applied and Environmental Microbiology 92(9):e01201-26. DOI 10.1128/aem.01201-26; Methods: Bacterial strains, minerals, and media; Biotite dissolution experiment; Dissolution of other minerals and gene expression analysis; Results: Generalizability; Figure 5; supplement Tables S6-S7 (pp11-12).
https://doi.org/10.1128/aem.01201-26 (accessed 2026-10-11) -
ncbi_pma2_2: NCBI GenBank CM125967.1, Priestia megaterium strain PMA2-2 chromosome; source feature and BioSample SAMN50659134 link inspected 11 October 2026. The species identifier does not identify the strain by itself.
https://www.ncbi.nlm.nih.gov/nuccore/CM125967.1 (accessed 2026-10-11) -
ncbi_megaterium: NCBI Taxonomy 1404, Priestia megaterium, species; taxonomy browser and taxonomy XML inspected 11 October 2026.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=1404&mode=Info (accessed 2026-10-11)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-11T11:14:04.745666Z |
codex (GPT-6; codex) | CREATE | Created hematite identity and primary PMA2-2 culture-associated dissolution record with feed, control and causal limits. |
Record source: data/records/hematite.yaml