Isolation of a native microbe with potential for bioleaching Te

CMI researchers at Ames Laboratory and Purdue University conducted the research for this highlight

To show characterization of A. ferriphilus GT2 isolated from gold mill tailings: Left is demonstration of Fe(II)-oxidation capability of GT2. Right is image from scanning electron micrograph (SEM) of biofilm harvested under Fe(II)-oxidizing conditions.
Characterization of A. ferriphilus GT2 isolated from gold mill tailings.
(A) Demonstration of Fe(II)-oxidation capability of GT2.
(B) Scanning electron micrograph (SEM) of biofilm harvested under Fe(II)-oxidizing conditions. 

Innovation
Iron-oxidizing and acid-generating microbes can extract Te from dilute sources such as mine tailings. 

Achievement
The indigenous acidophilic and iron-oxidizing bacterium Acidithiobacillus ferriphilus GT2 was isolated from gold tailings, and its genome was sequenced and annotated.

Significance and Impact

  • First complete genome sequence of an Acidithiobacillus ferriphilus species, providing a valuable resource for improving its utility in biomining.
  • Microbially oxidized iron, Fe(III), promotes sulfide mineral dissolution, leading to acid generation and metal release.
  • Strain GT2 forms biofilms on minerals; proximal generation of Fe(III) may enhance Te leaching from tailings as low-grade yet voluminous sources.

Hub Targets Addressed

  • Grand challenge: Unlocking unconventional resources.
  • Industry adoption of a technology for source diversification for a material other than REE or Li.

Complete annotated genome of Acidithiobacillus ferriphilus GT2 was submitted to Microbiology Resource Announcements.