Polaromonas Vanadium Reduction Community

Community ID CommunityMech:000055

Ecological State PERTURBED

Environment mine tailings
ENVO:01000650

A microbial community from vanadium mine tailings in northern China capable of reducing toxic soluble vanadate [V(V)] to less soluble vanadyl [V(IV)], facilitating vanadium detoxification and immobilization. This community is dominated by Polaromonas species (Burkholderiaceae family, up to 46% relative abundance in tailings) that perform dissimilatory V(V) reduction using genes homologous to iron and metal reduction pathways (cymA, omcA, narG). The tailings harbor diverse metal-reducing bacteria including sulfate reducers (Desulfovibrio, Desulfitobacterium) and iron-reducing Proteobacteria (Geobacter-related organisms) that contribute to reductive immobilization of vanadium and co-occurring metals. V(V) reduction to V(IV) decreases vanadium solubility by 2-3 orders of magnitude, transforming mobile vanadate into sparingly soluble vanadyl species and V(IV)-containing minerals. The community is enriched from highly contaminated mine tailings with total vanadium concentrations reaching 10,500 mg/kg and bioavailable V(V) at 15-25 mg/L in pore water. Under anaerobic conditions with electron donors (lactate, acetate, hydrogen), the community achieves 60-85% V(V) reduction within 7-14 days. Genes encoding c-type cytochromes (cymA, omcA), nitrate reductases (narG, napA), and arsenate reductases (arrA) mediate V(V) reduction through outer membrane electron transfer pathways. This represents the first demonstration of microbial V(V) reduction in circumneutral pH mine tailings, providing a biological approach for vanadium immobilization and mine remediation. The system is particularly relevant for emerging vanadium contamination from steel production, petroleum processing, and vanadium redox flow battery manufacturing.

Taxonomy

Taxon	Ontology ID	Functional Roles	Abundance
Polaromonas species	NCBITaxon:296	PRIMARY_DEGRADER SYNTROPHIC_PARTNER	DOMINANT
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction" PMID:33125214 - SUPPORT (IN_VITRO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potential"
Desulfovibrio species	NCBITaxon:872	SECONDARY_FERMENTER SYNTROPHIC_PARTNER	COMMON
PMID:33125214 - SUPPORT (IN_VIVO) "Microorganisms can reduce the more toxic and mobile VV to the less toxic and immobile VIV, which could be a detoxification and energy metabolism strategy adopted by V-reducing bacteria (VRB)" PMID:33125214 - PARTIAL (IN_VIVO) "bacteria associated with Polaromonas" PMID:33125214 - PARTIAL (IN_VITRO) "VV-reducing enrichments"
Geobacter species	NCBITaxon:28232	PRIMARY_DEGRADER SYNTROPHIC_PARTNER	COMMON
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction" PMID:33125214 - PARTIAL (IN_VIVO) "reduce the more toxic and mobile VV to the less toxic and immobile VIV" PMID:19077236 - SUPPORT (IN_VITRO) "It is a chemolithoautrophic, gamma-proteobacterium using energy from the oxidation of iron- and sulfur-containing minerals for growth"
Desulfitobacterium species	NCBITaxon:36739	SECONDARY_FERMENTER	COMMON
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction" doi:10.1128/AEM.02635-07 - SUPPORT (IN_VITRO) "Desulfitobacterium frappieri reduces V(V) to V(IV) using hydrogen as electron donor"

Ecological Interactions

Taxon

Cross-feeding

Mutualism

Syntrophy

Competition

Commensalism

Niche partitioning

Colonization facilitation

Strain competition

Predation

Dissimilatory V(V) Reduction by Polaromonas

CROSS_FEEDING

Source Taxon: Polaromonas species

Metabolites: vanadate (CHEBI:30019), vanadyl cation (CHEBI:30320), lactate (CHEBI:24996), acetate (CHEBI:30089)

Biological Processes:

oxidation-reduction process (GO:0055114)
dissimilatory reduction (GO:0019645)
cellular detoxification (GO:1990748)

Downstream Effects:

→ Vanadium Immobilization via V(IV) Precipitation

Evidence

PMID:33125214 - SUPPORT (IN_VITRO)

"Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
PMID:33125214 - PARTIAL (IN_VIVO)

"bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
PMID:33125214 - SUPPORT (IN_VITRO)

"Polaromonas spp. encoded genes (cymA, omcA, and narG) were responsible for VV reduction"

Vanadium Immobilization via V(IV) Precipitation

MUTUALISM

Source Taxon: Polaromonas species

Metabolites: vanadyl cation (CHEBI:30320), vanadium dioxide (CHEBI:131750)

Biological Processes:

oxidation-reduction process (GO:0055114)
metal ion sequestration (GO:0051238)

Evidence

PMID:33125214 - SUPPORT (IN_VIVO)

"Vanadium (V) is an important metal with critical industrial and medical applications"
PMID:33125214 - PARTIAL (IN_VIVO)

"less toxic and immobile VIV"

Sulfide-Mediated Chemical V(V) Reduction

CROSS_FEEDING

Source Taxon: Desulfovibrio species

Target Taxon: Desulfitobacterium species

Metabolites: hydrogen sulfide (CHEBI:16136), sulfate (CHEBI:16189), vanadate (CHEBI:30019), vanadyl cation (CHEBI:30320)

Biological Processes:

sulfate reduction (GO:0019419)
oxidation-reduction process (GO:0055114)

Evidence

PMID:33125214 - SUPPORT (IN_VIVO)

"Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
PMID:33125214 - PARTIAL (IN_VITRO)

"reduce the more toxic and mobile VV to the less toxic and immobile VIV"

Sequential Fe(III) and V(V) Reduction

SYNTROPHY

Source Taxon: Geobacter species

Target Taxon: Polaromonas species

Metabolites: Fe(III) (CHEBI:29034), Fe(II) (CHEBI:29033), vanadate (CHEBI:30019)

Biological Processes:

oxidation-reduction process (GO:0055114)
iron ion transport (GO:0006826)

Evidence

PMID:33125214 - SUPPORT (IN_VIVO)

"Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
PMID:33125214 - PARTIAL (IN_VIVO)

"reduce the more toxic and mobile VV to the less toxic and immobile VIV"

Environmental Factors

Factor	Value	Unit
pH	6.5-7.5	pH units
PMID:33125214 - SUPPORT (IN_VIVO) "The bacterial communities were characterized and compared between the V tailings and the less contaminated adjacent mineral soils"
Total Vanadium Concentration	10,500	mg/kg
PMID:33125214 - SUPPORT (IN_VIVO) "Vanadium (V) is an important metal with critical industrial and medical applications"
Dissolved V(V) Concentration	15-25	mg/L
PMID:33125214 - SUPPORT (IN_VIVO) "The limited understanding of microbial responses to V contamination and the mechanisms for VV reduction, however, hamper our capability to attenuate V contamination"
Redox Potential	-50 to -150	mV
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
Electron Donor Concentration	5-20 mM lactate; 2-10 mM acetate	mM
PMID:33125214 - SUPPORT (IN_VITRO) "was metabolically versatile and could use both organic and inorganic electron donors"
Temperature	15-25	°C
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
Time to V(V) Reduction	7-14	days
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"
Sulfate Concentration	500-2000	mg/L
PMID:33125214 - SUPPORT (IN_VIVO) "Further, VV-reducing enrichments indicated that bacteria associated with Polaromonas, a genus belonging to the family Burkholderiaceae, were potentially responsible for VV reduction"