Cupriavidus metallidurans

Cupriavidus metallidurans is a non-spore-forming, Gram-negative bacterium which is adapted to survive several forms of heavy metal stress.^[3][4][5]

Cupriavidus metallidurans
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Betaproteobacteria
Order:	Burkholderiales
Family:	Burkholderiaceae
Genus:	Cupriavidus
Species:	C. metallidurans
Binomial name
Cupriavidus metallidurans (Goris et al. 2001) Vandamme and Coenye 2004
Type strain
ATCC 43123, aka CH34
Synonyms
Ralstonia metallidurans Goris et al. 2001[1] Wautersia metallidurans (Goris et al. 2001) Vaneechoutte et al. 2004 (Not distinguished from Ralstonia eutropha until 2001.)[2]

As a model and industrial system

Cupriavidus metallidurans is a bacterial species that belongs to the same family as Ralstonia solanacearum, a plant pathogen.^[6]

This species is of ecological and industrial importance, as its relatives dominate mesophilic environments contaminated with heavy metals.^[2][7] C. metallidurans is used in the industrial sector for both heavy metal remediation and sensing.^[4]

This aerobic chemolithoautotroph is capable of growing in a mineral salts environment with H₂, O₂, and CO₂ without an organic carbon source.^[8] Its energy-providing subsystem is composed of only the hydrogenase, the respiratory chain, and the F1F0-ATPase, which remain separate from the anabolic subsystems.

C. metallidurans can also degrade xenobiotics in conditions with high levels of heavy metals.^[9]

Strain CH34 has adapted to these harsh conditions through multiple heavy-metal resistance systems, encoded by the two indigenous megaplasmids, pMOL28 and pMOL30, on its chromosome(s).^[3][4][10]

Ecology

A scanning electron microscope image of a gold nugget, revealing bacterioform (bacteria-shaped) structures

C. metallidurans plays a vital role, together with Delftia acidovorans, in the formation of gold nuggets. It precipitates metallic gold from a solution of gold(III) chloride, a compound highly toxic to most other microorganisms.^[11][12][13]

As a pathogen

A case of a 74 year old man infected with Cupriavidus metallidurans has been documented,^[14] possibly raising concerns about the safety of using the bacteria for industrial purposes.