Rammelsberg Cobalt-Nickel Tailings Consortium

Community ID CommunityMech:000057

Ecological State ENGINEERED

Environment mine tailing
ENVO:00000072

A mesophilic acidophilic bacterial consortium applied to bioleach cobalt, copper, and other valuable metals from sulfidic mine tailings at the Rammelsberg polymetallic massive sulfide deposit in the Harz Mountains, Germany. This consortium represents one of the only industrial-scale cobalt bioleaching processes globally and demonstrates exceptional efficiency in recovering critical battery materials from low-grade mine tailings. The adapted microbial community consists mainly of Acidithiobacillus ferrooxidans (iron-oxidizing) and Acidithiobacillus thiooxidans (sulfur-oxidizing), achieving 91% cobalt and 57% copper extraction from bulk tailings (Co 0.02%, Cu 0.12%) after 13 days in stirred tank reactors at 10% pulp density. The consortium exhibits synergistic cooperation between iron and sulfur oxidizers, where iron oxidation by At. ferrooxidans generates ferric iron that chemically oxidizes sulfide minerals, while sulfur oxidation by At. thiooxidans prevents elemental sulfur passivation and maintains low pH through sulfuric acid production. Mineralogical analysis revealed that cobalt occurs on the surface of framboidal pyrite and is mobilized through microbial attack. This system demonstrates the biotechnological potential for recovering critical materials (cobalt, copper, nickel) from mine waste through environmentally sustainable bioprocessing, addressing both resource recovery and mine tailings remediation challenges relevant to the circular economy and battery supply chains.

Taxonomy

Taxon	Ontology ID	Functional Roles	Abundance
Acidithiobacillus ferrooxidans	NCBITaxon:920	PRIMARY_DEGRADER	DOMINANT
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings are being developed through the recovery of valuable metals and critical raw materials and the transformation of the residual in clean mineral fraction to be used for the mass production of cement, concrete and construction products" doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "The mining of non-ferrous metals produces the largest volume of metal-containing, extractive waste in Europe, and about 29% of all the waste produced"
Acidithiobacillus thiooxidans	NCBITaxon:930	PRIMARY_DEGRADER SYNTROPHIC_PARTNER	DOMINANT
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "Cobalt dissolution kinetics were highly improved by the bacterial activity, whatever the consortium"

Ecological Interactions

Taxon

Cross-feeding

Mutualism

Syntrophy

Competition

Commensalism

Niche partitioning

Colonization facilitation

Strain competition

Predation

Iron Oxidation and Ferric Iron Generation

COMMENSALISM

Source Taxon: Acidithiobacillus ferrooxidans

Metabolites: Fe(II) (CHEBI:29033), Fe(III) (CHEBI:29034), oxygen (CHEBI:15379)

Biological Processes:

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

Downstream Effects:

→ Cobalt and Copper Mobilization from Sulfide Minerals

Evidence

PMID:39770610 - SUPPORT (IN_VITRO)

"It has emerged as a key player in biomining and bioleaching technologies thanks to its unique ability to mobilize a wide spectrum of elements, such as Li, P, V, Cr, Fe, Ni, Cu, Zn, Ga, As, Mo, W, Pb, U, and its role in ferrous iron oxidation and reduction"

Cobalt and Copper Mobilization from Sulfide Minerals

MUTUALISM

Source Taxon: Acidithiobacillus ferrooxidans

Target Taxon: Acidithiobacillus thiooxidans

Metabolites: Fe(III) (CHEBI:29034), cobalt(2+) (CHEBI:48828), copper(2+) (CHEBI:29036), sulfate (CHEBI:16189)

Biological Processes:

oxidation-reduction process (GO:0055114)

Downstream Effects:

→ Iron Oxidation and Ferric Iron Generation

→ Sulfur Oxidation and Acid Generation

Evidence

doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)

"This material still contains several sulfide minerals (pyrrhotite, pyrite, sphalerite, pentlandite, violarite, chalcopyrite) and significant amounts of metals (Zn, Ni, Cu, Co, rare earth elements)"
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)

"Cobalt dissolution kinetics were highly improved by the bacterial activity, whatever the consortium. This is consistent with the presence of Co in the pyrite in the secondary ore"

Sulfur Oxidation and Acid Generation

MUTUALISM

Source Taxon: Acidithiobacillus thiooxidans

Metabolites: elemental sulfur (CHEBI:27568), sulfuric acid (CHEBI:26836), sulfate (CHEBI:16189)

Biological Processes:

oxidation-reduction process (GO:0055114)
sulfur compound metabolic process (GO:0006790)

Downstream Effects:

→ Iron Oxidation and Ferric Iron Generation

Evidence

PMID:39770610 - SUPPORT (IN_VITRO)

"However, its use in biometallurgical applications poses environmental issues through its effect on the pH levels in bioleaching systems, which produce acid mine drainage in rivers and lakes adjacent to mines"
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO)

"In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings are being developed through the recovery of valuable metals and critical raw materials and the transformation of the residual in clean mineral fraction to be used for the mass production of cement, concrete and construction products"

Autotrophic Carbon Fixation in Acidic Environment

COMMENSALISM

Source Taxon: Acidithiobacillus ferrooxidans

Target Taxon: Acidithiobacillus thiooxidans

Metabolites: carbon dioxide (CHEBI:16526), ATP (CHEBI:15422)

Biological Processes:

carbon fixation (GO:0015977)
reductive pentose-phosphate cycle (GO:0019253)

Evidence

PMID:39770610 - SUPPORT (IN_VITRO)

"ferrooxidans catalyzes the extraction of elements by generating iron (III) ions in oxic conditions, which are able to react with metal sulfides"

Environmental Factors

Factor	Value	Unit
pH	1.5-2.5	pH units
PMID:39770610 - SUPPORT (IN_VITRO) "However, its use in biometallurgical applications poses environmental issues through its effect on the pH levels in bioleaching systems, which produce acid mine drainage in rivers and lakes adjacent to mines"
Temperature	30-35	°C
PMID:39770610 - SUPPORT (IN_VITRO) "ferrooxidans catalyzes the extraction of elements by generating iron (III) ions in oxic conditions, which are able to react with metal sulfides"
Pulp Density	10	% (w/v)
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "The mining of non-ferrous metals produces the largest volume of metal-containing, extractive waste in Europe, and about 29% of all the waste produced in the EU-28"
Reactor Configuration	2 L stirred tank reactors	liters
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "The study aimed to characterize the mineralogy of the secondary ore and perform bioleaching in 2 L-stirred tank reactors, with three microbial cultures growing at 42, 48 and 55 °C"
Bioleaching Duration and Metal Recovery	13	days
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "The first step of the NEMO concept consists of removing the sulfides remaining from primary bioleaching and extracting the metals in the residual material (known as ‘secondary ore’) using either enhanced bioleaching or an alkaline autoclave conversion processes"
Oxygen Supply	Aerobic	condition
PMID:39770610 - SUPPORT (IN_VITRO) "It has emerged as a key player in biomining and bioleaching technologies thanks to its unique ability to mobilize a wide spectrum of elements, such as Li, P, V, Cr, Fe, Ni, Cu, Zn, Ga, As, Mo, W, Pb, U, and its role in ferrous iron oxidation and reduction"
Tailings Mineralogy and Metal Grades	Framboidal pyrite with surface-associated cobalt	N/A
doi:10.1016/j.hydromet.2020.105484 - SUPPORT (IN_VITRO) "In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings are being developed through the recovery of valuable metals and critical raw materials and the transformation of the residual in clean mineral fraction to be used for the mass production of cement, concrete and construction products"