Ion-Adsorption REE Indigenous Community

Isolated Bacillus and Micrococcus strains from the Renju profile preferentially adsorbed HREEs in separate laboratory assays. In the Bacillus pumilus cell-wall comparison, removing teichoic acids reduced total REE adsorption from 65.5 to 17.8 percent and removed HREE preference; residual binding remained. Freeze-dried cells retained adsorption, consistent with passive surface binding rather than active metal transport. Ytterbium/phosphorus colocalization and spectroscopy support wall binding groups, not a resolved bond geometry or proof that ionic radius is the sole cause. The canonical genera represent separately tested isolates, not measured commensalism between them or every strain in either genus.

Participating Taxa: Bacillus, Micrococcus

Metabolites: yttrium(3+) (CHEBI:49962 · MediaIngredientMech · CMMMech), ytterbium(3+) (CHEBI:49980 · MediaIngredientMech · CMMMech)

Evidence

• PMID:35708325 - SUPPORT (IN_VITRO)
  "Taking advantage of bacteria strains isolated from the profile, Gram-positive bacteria affiliated with Bacillus and Micrococcus preferentially adsorbed HREEs, and teichoic acids in the cell wall served as the main sites for HREE adsorption, leading to an enrichment of HREEs in the deposit"
• PMID:35708325 - SUPPORT (IN_VITRO)
  "teichoic acids in the cell walls of G+ bacteria lead to REE fractionation"
• PMID:35708325 - SUPPORT (IN_VITRO)
  "surface carboxyl and phosphate groups are active sites for REE adsorption"
• PMID:35708325 - SUPPORT (IN_VITRO)
  "decreased the REE adsorption from 65.5% to only 17.8%"

HYPOTHESIZED - microbial organic acids and other ligands could weather minerals and release REEs in the Renju profile. The primary discussion combines community/geochemical associations with weathering functions known from prior literature; it does not measure these routes in every listed phylum or isolate direct Proteobacteria-to-Actinobacteria transfer. The canonical bacterial and fungal phyla are contextual groups, not a demonstrated four-partner cross-feeding unit. An orders-of-magnitude acceleration relative to abiotic weathering was not established in the inspected study.

Participating Taxa: Proteobacteria, Actinobacteria, Ascomycota, Basidiomycota

Metabolites: citric acid (CHEBI:30769 · MediaIngredientMech · CMMMech), oxalic acid (CHEBI:16995 · MediaIngredientMech · CMMMech), organic molecular entity (CHEBI:50860 · MediaIngredientMech · CMMMech)

Evidence

• PMID:35708325 - PARTIAL (IN_VIVO)
  "These findings not only elucidate the crucial contribution of fungi and bacteria in the supergene REE mineralization but also provide insights into efficient utilization of mineral resources via a biological pathway"
• PMID:35708325 - PARTIAL (IN_VIVO)
  "Both fungi and bacteria contributed to the accumulation of REEs"

Field geochemistry shows HREE enrichment in the Renju B horizon, with total HREE concentrations of 56-184 ppm and a total-REE maximum of 776 ppm near 6 m. These are elemental sums, not the concentration or speciation of a single yttrium ion. The sampled profile extends to 45 m and uses A, B and P horizons. Microbial composition correlations and isolate adsorption support a proposed biological contribution alongside clay/mineral binding and hydrology; they do not quantify the microbial share of deposit formation. The canonical taxa are a sampled community subset, not proven joint causes or reciprocal beneficiaries of enrichment.

Participating Taxa: Proteobacteria, Acidobacteria, Actinobacteria, Bacillus, Micrococcus, Ascomycota, Basidiomycota

Evidence

• PMID:35708325 - SUPPORT (IN_VIVO)
  "the B horizon is rich in HREEs"

HYPOTHESIZED - fungal organic acids and mineral-surface interactions could contribute to REE mobilization. Ascomycota/Basidiomycota profiles and selected fungal-genus correlations are positive community observations; the exact weathering functions are discussed partly from prior literature. The study does not isolate mutual benefit between these phyla, complementary enzyme action, direct fungal-to-bacterial transfer or an orders-of-magnitude rate increase in this profile. The canonical phyla delimit the represented fungal groups, not a resolved two-member consortium.

Participating Taxa: Ascomycota, Basidiomycota

Metabolites: citric acid (CHEBI:30769 · MediaIngredientMech · CMMMech), oxalic acid (CHEBI:16995 · MediaIngredientMech · CMMMech)

Evidence

• PMID:35708325 - PARTIAL (IN_VIVO)
  "Both fungi and bacteria contributed to the accumulation of REEs"
• PMID:35708325 - PARTIAL (IN_VIVO)
  "These findings not only elucidate the crucial contribution of fungi and bacteria in the supergene REE mineralization but also provide insights into efficient utilization of mineral resources via a biological pathway"

Acidobacteria averaged 14.6 percent of bacterial sequences and generally decreased with depth to 40 m before a slight increase at 45 m. The primary discussion invokes an oligotrophic K-strategist interpretation, not increasing deep-profile dominance. Neither taxonomic abundance nor that ecological interpretation demonstrates Acidobacteria ligand production, measured REE mobilization, exclusion of Proteobacteria or a benefit supplied to them. Preserve the observed distribution without assigning a phylum-wide biochemical pathway.

Participating Taxa: Acidobacteria

Evidence

• PMID:35708325 - SUPPORT (IN_VIVO)
  "tends to decrease with increasing depth"