Hualgayoc Acidic Sulfate-Reducing AMD Consortium

Community ID CommunityMech:000353

Ecological State ENGINEERED

Environment acidophilic sulfate-reducing synthetic AMD enrichment — ontology label: active anaerobic enrichment culturing unit
ENVO:01001825 · HabitatMech ↗

Modeled Environment acid mine drainage
ENVO:00001997 · HabitatMech ↗

An engineered acidophilic sulfate-reducing bacterial enrichment derived from acidic sediments of the abandoned BSA-100 mining tunnel in Hualgayoc, Cajamarca, Peru, and assayed for bioremediation of synthetic acid mine drainage at pH 2.9. The glycerol-fed, sulfate-amended enrichment raised the synthetic AMD pH to 6.1 and removed 100% of Zn2+, more than 99% of Fe2+, and more than 94% of Al3+ after 160-200 days. Genome-resolved metagenomics recovered two high-quality dominant sulfate-reducing MAGs, Desulfosporosinus sp. MAG003 and Acididesulfobacillus sp. MAG013, whose inferred carbon metabolisms suggest a cooperative route in which Desulfosporosinus starts sulfate reduction on glycerol at pH around 3.0 and Acididesulfobacillus continues sulfate reduction on acetate once the culture rises to pH around 4.0.

Taxonomy

Taxon	Ontology ID	Functional Roles	Abundance
Desulfosporosinus sp. MAG003 — ontology label: Desulfosporosinus	NCBITaxon:79206 · TaxonMech · TraitMech	PRIMARY_DEGRADER SYNTROPHIC_PARTNER CROSS_FEEDER	DOMINANT
PMID:42029028 - SUPPORT (COMPUTATIONAL) "Taxonomic classification based on 115 bacterial marker genes showed affiliation of MAG003 to Desulfosporosinus sp. and MAG013 to Acididesulfobacillus sp." PMID:42029028 - SUPPORT (COMPUTATIONAL) "Regarding the sulfur cycle, the occurrence of sat, aprAB, and dsrAB genes confirmed the presence of the whole dissimilatory sulfate reduction pathway in both MAGs." PMID:42029028 - SUPPORT (COMPUTATIONAL) "Desulfosporosinus (68.3%) is able to oxidize glycerol to acetate"
Acididesulfobacillus sp. MAG013 — ontology label: Acididesulfobacillus	NCBITaxon:2924872 · TaxonMech · TraitMech	PRIMARY_DEGRADER SYNTROPHIC_PARTNER CROSS_FEEDER	DOMINANT
PMID:42029028 - SUPPORT (COMPUTATIONAL) "Taxonomic classification based on 115 bacterial marker genes showed affiliation of MAG003 to Desulfosporosinus sp. and MAG013 to Acididesulfobacillus sp." PMID:42029028 - SUPPORT (COMPUTATIONAL) "Regarding the sulfur cycle, the occurrence of sat, aprAB, and dsrAB genes confirmed the presence of the whole dissimilatory sulfate reduction pathway in both MAGs." PMID:42029028 - SUPPORT (COMPUTATIONAL) "Genes involved in acetate oxidation via the tricarboxylic acid (TCA) pathway (icd, korABCD, sucCD, sdhABCD, and fumAB) were found in Acididesulfobacillus-MAG"

Ecological Interactions

The graph shows only explicitly linked interaction participants. Community members without an asserted participant link are omitted; membership alone does not imply an interaction.

Taxon

Cross-feeding

Glycerol-to-Acetate Sulfate Reduction

CROSS_FEEDING

PARTIAL - the authors propose Desulfosporosinus sp. MAG003 as an initiator of glycerol-associated sulfate reduction and acetate production near pH 3. Bulk chemistry and taxon profiles support this model, but both dominant MAGs encode glycerol-to-acetate potential and do not establish exclusive MAG003 flux. The canonical participant remains MAG003 for this proposed initiating role; possible minor acidogens remain unresolved. Inoculum was added again on days 32 and 86, so the time course is not unassisted succession.

Participating Taxa: Desulfosporosinus sp. MAG003

Metabolites: glycerol (CHEBI:17754 · MediaIngredientMech · CMMMech), acetate (CHEBI:30089 · MediaIngredientMech · CMMMech), sulfate (CHEBI:16189 · MediaIngredientMech · CMMMech), hydrogen sulfide (CHEBI:16136 · MediaIngredientMech · CMMMech)

Biological Processes:

dissimilatory sulfate reduction (GO:0019420 · PathwayMech)

Downstream Effects:

→ Acetate-Fed Acididesulfobacillus Sulfate Reduction

PARTIAL - proposed glycerol oxidation can supply acetate to the later MAG013-associated sulfate-reducing route as the medium becomes less acidic. Bulk chemistry and genomes support the model, but do not resolve the exact donor-to-recipient flux, demonstrate acetate-toxicity rescue or isolate pH from reinoculation and other time-varying conditions.

Evidence

PMID:42029028 - PARTIAL (IN_VITRO)

"Desulfosporosinus initiated sulfate reduction at pH ~3.0 with glycerol as the carbon source and acetate as the waste product."
PMID:42029028 - PARTIAL (COMPUTATIONAL)

"While genes coding for glycerol, pyruvate, and acetyl-CoA oxidation (from glycerol to acetate) were found in both MAGs"

Acetate-Fed Acididesulfobacillus Sulfate Reduction

CROSS_FEEDING

PARTIAL - the authors propose that Acididesulfobacillus sp. MAG013 consumes acetate while reducing sulfate after pH rises toward 4. TCA-cycle annotations support a potential acetate-oxidation route, not measured MAG013-specific carbon dioxide flux, an exclusive substrate role or a selectively established pH threshold. Acetate removal could relieve organic-acid stress, but toxicity mediation and complete carbon mineralization were not demonstrated; residual acetate remained at day 160.

Participating Taxa: Desulfosporosinus sp. MAG003, Acididesulfobacillus sp. MAG013

Metabolites: acetate (CHEBI:30089 · MediaIngredientMech · CMMMech), carbon dioxide (CHEBI:16526 · MediaIngredientMech · CMMMech), sulfate (CHEBI:16189 · MediaIngredientMech · CMMMech)

Biological Processes:

acetate catabolic process (GO:0045733 · PathwayMech)
dissimilatory sulfate reduction (GO:0019420 · PathwayMech)

Evidence

PMID:42029028 - PARTIAL (IN_VITRO)

"Once pH rose to ~4.0, Acididesulfobacillus continued with sulfate reduction with acetate as a carbon source"
PMID:42029028 - PARTIAL (COMPUTATIONAL)

"genes for the TCA cycle (from acetate to CO2) were mainly found in Acididesulfobacillus-MAG"

Associated Datasets

Dataset	Type	Repository	Accession
Hualgayoc aSRB synthetic AMD amplicons and metagenomes NCBI BioProject containing 16S rRNA amplicon and metagenomic sequencing data from the Hualgayoc acidophilic sulfate-reducing enrichment assayed for synthetic AMD bioremediation.	METAGENOMICS	NCBI_BIOPROJECT	PRJNA1217137

Knowledge gaps & discussions (2)

KNOWLEDGE_GAP OPEN Stage-1 Negativicutes and Clostridiaceae may have fermented glycerol to acetate before sulfate reduction became active, but they were not resolved as named MAG members in the source; this record therefore keeps the high-quality aSRB MAGs as members and treats the minor fermenters as an open compositional detail.

Resolving the acidogenic fermenters with MAGs would clarify how much of the early glycerol-to-acetate flux was performed by Desulfosporosinus versus non-aSRB community members.

Attaches to: taxonomy

KNOWLEDGE_GAP OPEN Which MAGs drive carbon flow, and how should the positive remediation outcome enter the graph?

Biotic treatment versus abiotic controls supports positive sulfate-reducing chemistry, pH increase and dissolved-metal removal, independently of inferred MAG assignments. Bulk 16S rRNA transcripts were measured; this is not MAG-resolved metabolic expression. Relative amplicon and metagenome profiles are different measurements and do not resolve flux. Both dominant MAGs have glycerol-to-acetate potential; other acidogens and organic amendments prevent assuming a closed two-member carbon balance. Mineral saturation modeling and poorly crystalline XRD do not prove exact precipitate identities; cell coating does not identify every coated cell as a sulfate reducer or exclude sulfide/acetate toxicity. The missing positive metal-removal/neutralization outcome structure remains unresolved under #1504. The original #815 rendering complaint was addressed by removal in merged PR814; restoring source-backed outcome structure is a distinct task. One-community Edison dry run succeeded without API calls or charges; the report and source-backed node/arrow extension remain pending specific provider authorization. Preserve #816's already-present MAG003-only initiating participant. Existing minor-acidogen discussion and non-graph blocks remain unchanged, not recertified.

Attaches to: ecological_interactions#Glycerol-to-Acetate Sulfate Reduction, ecological_interactions#Acetate-Fed Acididesulfobacillus Sulfate Reduction

External Resources

Name	Repository	Resource ID
Primary publication - Hualgayoc acidophilic sulfate-reducing AMD consortium Open-access Applied and Environmental Microbiology study combining acidic sediment enrichment, synthetic AMD bioremediation, geochemistry, amplicon profiling, and metagenomics to resolve a Desulfosporosinus- and Acididesulfobacillus-dominated aSRB consortium.	OTHER	PMID:42029028
PMID:42029028 - SUPPORT (IN_VITRO) "Desulfosporosinus and Acididesulfobacillus dominate an acidophilic sulfate-reducing bacteria consortium during acid mine drainage bioremediation."

Environmental Factors

Factor	Value	Unit
Synthetic AMD acidity and sulfate	pH 2.9; 50.53 mM sulfate	N/A
PMID:42029028 - SUPPORT (IN_VITRO) "The final sAMD mixture contained a theoretical value of 50.53 mM sulfate and a pH of 2.9."
Main dissolved metals in synthetic AMD	Fe2+ 40.25 mM; Al3+ 5.39 mM; Zn2+ 3.97 mM	N/A
PMID:42029028 - SUPPORT (IN_VITRO) "with Fe2+ (40.25 mM), Al3+ (5.39 mM), and Zn2+ (3.97 mM) as the main dissolved metals."
Metal removal and pH endpoint	pH 6.1; 100% Zn2+, >99% Fe2+, >94% Al3+ removed	N/A
PMID:42029028 - SUPPORT (IN_VITRO) "At the end of the incubation, the final pH reached 6.1 and 100% of Zn2+, >99% of Fe2+, and >94% of Al3+ were removed by the aSRB consortium"

Growth Media

pH-2.5 glycerol sulfate aSRB enrichment medium

pH 2.5

Temperature 30 C

Atmosphere ANAEROBIC

Composition

Component	Concentration	Unit	CHEBI
glycerol · MediaIngredientMech	5	mM	CHEBI:17754
sodium sulfate · MediaIngredientMech	10	mM	N/A
yeast extract · MediaIngredientMech	0.1	g/L	N/A
L-cysteine · MediaIngredientMech	0.5	g/L	N/A

Preparation notes: Mineral salts medium was adjusted to pH 2.5, degassed with N2, sealed under an N2/CO2 headspace, supplied with sediment at 10% w/v, and transferred three times under the same static, anoxic, dark 30 C conditions.

Evidence

PMID:42029028

"100 mL glass serum bottles were filled with 50 mL of mineral salts medium (MSM)"

PMID:42029028

"The medium was supplemented with 0.1 g L−1 of yeast extract, 0.5 g L−1 of L-cysteine, and 1.42 g L−1 (10 mM) of Na2SO4 as an electron acceptor."

PMID:42029028

"glycerol was added to the medium as an electron donor and carbon source from a 1 M autoclaved anoxic stock to obtain a final concentration of 5 mM."

PMID:42029028

"Three transfers were performed in total."

glycerol synthetic acid mine drainage medium

pH 2.9

Temperature 30 C

Atmosphere ANAEROBIC

Composition

Component	Concentration	Unit	CHEBI
sulfate · MediaIngredientMech	50.53	mM	CHEBI:16189
glycerol · MediaIngredientMech	25	mM	CHEBI:17754

Preparation notes: Synthetic AMD was formulated from metal and iron stocks to mimic average BSA-100 AMD chemistry. The pH-2.9 medium was supplemented with vitamins, 25 mM glycerol, and 10% enriched aSRB inoculum, with more inoculum added on days 32 and 86.

Evidence

PMID:42029028

"The experiment was performed in 1,000 mL Schott bottles containing 500 mL of sAMD."

PMID:42029028

"The final sAMD mixture contained a theoretical value of 50.53 mM sulfate and a pH of 2.9."

PMID:42029028

"The bottles were then supplemented with vitamins, glycerol as a carbon source (25 mM), and with the previously enriched aSRB consortium (10%)."

PMID:42029028

"Bottles were incubated in the dark at 30°C and monitored for 160 days for physicochemical parameters"

Cross-Mech Suite Links

Explore related entities across the CultureBotAI X-Mech knowledge bases:

HabitatMech: acidophilic sulfate-reducing synthetic AMD enrichment ↗ TaxonMech: Desulfosporosinus sp. MAG003 ↗ TraitMech: Desulfosporosinus sp. MAG003 ↗ TaxonMech: Acididesulfobacillus sp. MAG013 ↗ TraitMech: Acididesulfobacillus sp. MAG013 ↗ CMMMech (Critical Minerals & REE) ↗ CultureMech Growth Media ↗ PathwayMech Pathways ↗