Potential for "Methanosarcina" to contribute to uranium reduction during acetate-promoted groundwater bioremediation

• Dawn E Holmes ^[1] ; Roberto Orelana ^[2] ; Ludovic Giloteaux ^[3] ; Li-Ying Wang ^[2] ; Pravin Shrestha ^[4] ; Kenneth Williams ^[5] ; Derek R Lovley ^[2] ; Amelia-Elena Rotaru ^[6]
  1. [1] Western New England University

     Western New England University

     City of Springfield, Estados Unidos

     
  2. [2] University of Massachusetts Amherst

     University of Massachusetts Amherst

     Town of Amherst, Estados Unidos

     
  3. [3] Cornell University

     Cornell University

     City of Ithaca, Estados Unidos

     
  4. [4] University of California, Berkeley

     University of California, Berkeley

     Estados Unidos

     
  5. [5] Lawrence Berkeley National Laboratory

     Lawrence Berkeley National Laboratory

     Estados Unidos

     
  6. [6] University of Southern Denmark

     University of Southern Denmark

     Dinamarca

     

  Mostrar afiliaciones +
• Localización: Microbial ecology, ISSN-e 1432-184X, ISSN 0095-3628, Vol. 76, Nº. 3, 2018, págs. 660-667
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Previous studies of acetate-promoted bioremediation of uranium-contaminated aquifers focused on Geobacter because no other microorganisms that can couple the oxidation of acetate with U(VI) reduction had been detected in situ. Monitoring the levels of methyl CoM reductase subunit A (mcrA) transcripts during an acetate-injection field experiment demonstrated that acetoclastic methanogens from the genus Methanosarcina were enriched after 40 days of acetate amendment. The increased abundance of Methanosarcina corresponded with an accumulation of methane in the groundwater. In order to determine whether Methanosarcina species could be participating in U(VI) reduction in the subsurface, cell suspensions of Methanosarcina barkeri were incubated in the presence of U(VI) with acetate provided as the electron donor. U(VI) was reduced by metabolically active M. barkeri cells; however, no U(VI) reduction was observed in inactive controls. These results demonstrate that Methanosarcina species could play an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth of Geobacter species. The results also suggest that Methanosarcina have the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments.