Otavite mineral
Otavite is the cadmium carbonate mineral CdCO3 in the calcite group, distinct from elemental cadmium, dissolved Cd ions, cadmium sulfides and unspecified cadmium-bearing precipitates. The September 2026 IMA list gives grandfathered status and original-description year 1906, not a unique approval accession. The curated laboratory study tentatively assigns a cell-associated synthetic precipitate to otavite; it does not establish a pure mineral product or the origin of natural otavite. No cadmium criticality designation is inherited.
Microbial & Biochemical Mechanisms (1)
Tentative otavite formation associated with a ureolytic bacterial culture
biomineralization
Microbial
Associated Organisms:
Serratia marcescens (NCBITaxon:615)
Urease-producing strain C7-12 removed dissolved cadmium from laboratory broth and developed cell-associated particles whose XRD signal the authors considered most likely otavite. Urea consumption, increasing pH and operational cadmium fractions are consistent with carbonate precipitation occurring alongside adsorption. The phase assignment remains tentative, and neither microbial necessity nor a phase-specific recovery yield was established.
Experimental Context & Analytical Limits:
Yang2026 Sections 2.1-2.8 and 3.1 describe C7-12 isolated among urease-producing bacteria from maize rhizosphere soil in a lead-zinc mining area. The authors assigned Serratia marcescens from a 100% 16S sequence match and reported deposit GDMCC65568; the complete article and supplement supply no sequence accession, and the deposit is retained as author-reported. NCBITaxon:615 maps the species name, not the strain or deposit. LB contained 5 g/L yeast extract, 10 g/L peptone and 5 g/L NaCl. The initial screening used 100 mL broth with 30 g/L urea, 2% inoculum, 30 degrees C and 160 rpm for 48 hours. One-factor-at-a-time experiments then selected the separate Table 2 conditions of 1 mg/L initial Cd, 20 g/L urea, 2% inoculum, initial pH 6, 30 degrees C and 48 hours. Experiments were described as triplicated. These are supplied soluble-Cd laboratory cultures, not natural otavite dissolution or ore extraction. The main text does not identify the Cd stock salt or fully describe XRD sample preparation; Section 2.8 identifies a Rigaku Ultima IV instrument. The separate soil-extract experiments are not the phase-specific basis of this mechanism.
Yang2026 Sections 2.1-2.8 and 3.1 describe C7-12 isolated among urease-producing bacteria from maize rhizosphere soil in a lead-zinc mining area. The authors assigned Serratia marcescens from a 100% 16S sequence match and reported deposit GDMCC65568; the complete article and supplement supply no sequence accession, and the deposit is retained as author-reported. NCBITaxon:615 maps the species name, not the strain or deposit. LB contained 5 g/L yeast extract, 10 g/L peptone and 5 g/L NaCl. The initial screening used 100 mL broth with 30 g/L urea, 2% inoculum, 30 degrees C and 160 rpm for 48 hours. One-factor-at-a-time experiments then selected the separate Table 2 conditions of 1 mg/L initial Cd, 20 g/L urea, 2% inoculum, initial pH 6, 30 degrees C and 48 hours. Experiments were described as triplicated. These are supplied soluble-Cd laboratory cultures, not natural otavite dissolution or ore extraction. The main text does not identify the Cd stock salt or fully describe XRD sample preparation; Section 2.8 identifies a Rigaku Ultima IV instrument. The separate soil-extract experiments are not the phase-specific basis of this mechanism.
Curated Evidence Points:
Partial
Source:
yang2026
Section 3.3.4 and Figure 7B compare C7-12 before and after Cd treatment at 48 hours. The authors assign two weak reflections at 23.49 and 30.28 degrees to CdCO3 using a reference pattern they label ICSD 01-072-1939, and describe the surface substance as most likely otavite. The displayed signal occurs on a substantial bacterial background. No phase fraction, refined structure, isolated pure product or raw diffraction dataset is supplied. Figure 6 shows particles and C, N, O and Cd by SEM-EDS, while Figure 7A shows FTIR changes; these observations alone do not distinguish a crystalline mineral species. The record retains the source's provisional assignment rather than treating CdCO3 composition as conclusive identification.
Support
Source:
yang2026
Sections 2.5-2.6 and 3.2, Figures 2-3 and Table 2 support dissolved-Cd removal under the stated culture conditions. Table 2 reports 84.61 plus or minus 5.81 percent removal for the optimized single-Cd treatment. The denominator is initial solution Cd, compared with Cd remaining in the centrifuged supernatant measured by flame atomic absorption, not a mass of purified otavite or recovered cadmium. Other one-factor screening percentages refer to different conditions and are not substituted for this table result. No field or industrial deployment is demonstrated.
Partial
Source:
yang2026
Figures 2-5 compare Cd concentrations and urea doses, including zero-urea treatment with residual Cd removal; Figures 6-7 include cells without added Cd. The inspected complete main and supplement do not describe matched uninoculated, pH-matched chemical, killed-cell or urease-inhibited precipitation controls. Urea-related trends and correlations therefore do not isolate a uniquely biological contribution or demonstrate that viable cells are required at the moment of precipitation. Section 4.2 itself calls for bacterial survival measurements. Enzyme-specific causation and a measured intracellular transport pathway are not established.
Partial
Source:
yang2026
Section 2.7, Figure 4 and supplementary Figure S2 define operational fractions from supernatant, flask-wall wash, EDTA-labelled surface extraction and digested pellet. Extracellular precipitation is calculated by subtraction from total Cd; it is not a direct otavite-specific measurement. Section 4.2 acknowledges nonselective extraction and possible speciation changes. These fractions do not establish intracellular localization or quantify how much removed Cd entered otavite. Sections 3.4-3.5 and Figures 8-11 concern distinct soil-solution arms with other source-assigned phases and possible inherited microminerals; their removal rates are not otavite yields. Although Section 3.3.4 invokes a solubility product to suggest environmental stability, Section 4.3 identifies long-term stability testing as future work, so durability is not treated as measured here.
Sources & References
-
ima_2026_09: IMA-CNMNC. The New IMA List of Minerals, September 2026. Otavite row, PDF page 161; page 1 defines grandfathered status and original-description years. Retained complete original rechecked.
https://cnmnc.units.it/files/editor/IMA_Master_List_(2026-09).pdf (accessed 2026-10-14) -
handbook_otavite: Handbook of Mineralogy. Otavite, version 1 (2001-2005), complete one-page species entry, crystal data, synthetic powder pattern and calcite group assignment. Identity context, not a microbial experiment.
https://www.handbookofmineralogy.org/pdfs/otavite.pdf (accessed 2026-10-14) -
yang2026: Yang, Q., Li, X., Cao, J., He, S., He, C., Tu, C., Zhou, K., Liang, X. and Zhan, F. (2026). Urea-Mediated Biomineralization and Adsorption of Heavy-Metal Ions in Solution by the Urease-Producing Bacteria C7-12. Microorganisms 14(1), 171. Complete 17-page original, Figures 1-11, Tables 1-2, and official two-page supplement with Table S1 and Figures S1-S5.
https://doi.org/10.3390/microorganisms14010171 (accessed 2026-10-14) -
ncbi_serratia: NCBI Taxonomy 615. Serratia marcescens, species-rank entry. This mapping does not identify or independently authenticate experimental strain C7-12.
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=615&mode=Info (accessed 2026-10-14)
Curation History
| Timestamp | Curator | Action | Summary |
|---|---|---|---|
2026-10-14T20:49:08Z |
codex (GPT-6; codex) | CREATE | Created a distinct otavite mineral owner from complete Yang2026 primary and official SI, preserving tentative phase assignment, culture and strain boundaries, unmatched causal controls and solution-removal denominators. |
Record source: data/records/otavite.yaml