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Copper autoclave slime secondary resource

Tellurium-containing processing residue described by Bonificio and Clarke as an effluent from processing tellurium from copper anode slime. The experimentally tested material was a dried powder supplied by the Freeport-McMoRan Copper and Gold refinery in El Paso, Texas. This downstream residue is distinct from untreated copper anode slime, copper ore, elemental tellurium and the separate commercial tellurium compounds used in the study. Its bulk elemental composition, mineral phases and original processing conditions were not reported. No criticality-list status is inferred from its constituents or the article's historical discussion of tellurium.

Microbial & Biochemical Mechanisms (1)

EPR3-associated elemental and volatile tellurium formation from autoclave slime

redox transformation Microbial

Associated Organisms: Pseudoalteromonas (NCBITaxon:53246)

Growing Pseudoalteromonas sp. EPR3 on artificial-seawater agar with copper autoclave slime produced Raman-confirmed elemental tellurium in sampled bacterial-lawn regions physically separated from the feed powder. A tellurium signal was also detected in the headspace above extracted agar samples. The observations support microbial tellurium transformation in this laboratory residue assay. Dissolution followed by transport of a soluble tellurium species is a supported interpretation; the dissolved species, volatile molecular identity and intracellular reaction sequence were not directly established.

Experimental Context & Analytical Limits:
Source-reported strain EPR3, designated DSMZ 28475 in the article, was supplied by C. Vetriani and described as isolated from East Pacific Rise hydrothermal-vent fluid. The organism identifier below resolves only the genus; no species or independently verified strain accession is assigned. Artificial seawater was sterilized at 121 degrees C for 15 minutes and solidified with 1.5% wt/vol agar in plates 10 cm in diameter and 1.5 cm high. Plates received 100 microliters of fully grown EPR3 culture at OD600 0.7 and approximately 0.1 g dried slime at the center, then were incubated aerobically for 48 h at 37 degrees C. The study describes circumneutral measured pH in its discussion but gives no numeric slime-assay pH, final cell concentration or plate agar volume. The artificial-seawater recipe is cited to earlier work rather than reproduced. Matched slime-containing plates without EPR3 were described as sterile controls; the slime's own sterilization treatment and verification of control sterility were not specified. No subsequent product isolation, recovery yield, purity, complete tellurium balance or industrial microbial operation was demonstrated.
Curated Evidence Points:
Accepted manuscript Methods, printed pages 6–8, Results page 12 and Figure 7a,d: the slime plate developed light-brown growth after 48 h. Raman spectra from the boxed region away from the original slime showed peaks assigned to elemental tellurium, compared with reference spectra in Figure 1. The authors report no visible change or feed movement on corresponding plates without EPR3. Photographs were uniformly adjusted for brightness, contrast and saturation; coloration alone is not a quantitative yield. Raman sensitivity was not quantified, and the measurements do not establish an isolated phase-pure product or exclusive intracellular localization.
Methods printed page 8 and Figure 3 with its caption: headspace from extracted slime-associated agar samples gave an ICP-MS tellurium signal at mass-to-charge ratio 125 after the 48 h assay. The authors report no detected gaseous tellurium for uninoculated sterile-source controls. Figure 3 plots instrumental counts over seconds of sampling, not accumulated tellurium mass, gas evolution rate or extraction percentage. No calibrated slime-specific volatile yield or biological replicate uncertainty is supplied. Detection of tellurium does not identify dimethyl telluride or prove methylation.
Context_only Source: bonificio2014
Table 1 and the separate dissolved-compound assay on printed pages 8–9 report 0.066 mmol/L dissolved tellurium after approximately 0.1 g slime was incubated in 5 g sterile liquid artificial seawater for 48 h at 37 degrees C with shaking. Table 1 explicitly states absence of EPR3; this is abiotic dissolution, not a bioleaching yield or a measurement from the agar treatment. The source gives liquid ICP-MS sensitivity as 20 nmol/L. The 93% solution depletion in Figure 5 concerns a separate potassium-tellurite experiment and is not assigned to slime.
Discussion and Figure 8 propose tellurite transport, reversible intracellular reduction/oxidation, methylation through the Challenger mechanism and steady-state cycling. These are hypotheses rather than a genetically or enzymatically demonstrated pathway. The authors explicitly leave the volatile species unidentified and discuss alternative intermediates. No direct measurement establishes the starting slime's tellurium oxidation state, complete conversion, selectivity against co-elements or the product purity and yield needed for a recovery process. The study's industrial feed origin and proposed applications do not demonstrate industrial deployment.
TaxID 53246 resolves to the genus Pseudoalteromonas. It does not authenticate EPR3 or demonstrate that all members share the observed activity. The DSMZ catalogue route did not resolve a strain entry during this assessment, so DSMZ 28475 remains source-reported text.

Sources & References

  1. bonificio2014: Bonificio WD and Clarke DR (2014). Bacterial recovery and recycling of tellurium from tellurium-containing compounds by Pseudoalteromonas sp. EPR3. Journal of Applied Microbiology 117(5):1293–1304. DOI 10.1111/jam.12629; Harvard accepted-manuscript copy, complete 37-page repository PDF including cover, Table 1 and Figures 1–8. Slime-specific evidence: Methods, Results subsection on devices and autoclave slime, Table 1, Figure 3 and Figure 7a,d.
    https://doi.org/10.1111/jam.12629 (accessed 2026-10-12)
  2. harvard_accepted: Harvard DASH repository record for Bonificio and Clarke (2014), DOI 10.1111/jam.12629; institutional authorship, citation and accepted manuscript provenance. Full PDF acquired from its public bitstream content link; publisher-layout version was not acquired.
    https://dash.harvard.edu/entities/publication/73120378-d1ea-6bd4-e053-0100007fdf3b (accessed 2026-10-12)
  3. ncbi_pseudoalteromonas: NCBI Taxonomy 53246, Pseudoalteromonas, genus rank; checked 12 October 2026. Genus identity only, not a strain-specific EPR3 accession or verification of the reported DSMZ 28475 deposit.
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=53246&mode=Info (accessed 2026-10-12)

Curation History

Timestamp Curator Action Summary
2026-10-12T12:34:21Z codex (GPT-6; codex) CREATE Created the distinct downstream copper autoclave slime resource and scoped laboratory EPR3 transformation from the complete institutional accepted manuscript. Retained sterile dissolution, nonquantitative headspace detection, unresolved molecular pathways and recovery limits. Independent scientific review is recorded separately.

Record source: data/records/copper-autoclave-slime.yaml