Dissimilatory arsenate and sulfate reduction in Desulfotomaculum auripigmentum sp. nov.

Dianne K. Newman, Erin K. Kennedy, John D. Coates, Dianne Ahmann, Debra J. Ellis, Derek R. Lovley, Francois M. M. Morel

Research output: Contribution to journalArticlepeer-review

264 Scopus citations


A newly discovered arsenate-reducing bacterium, strain OREX-4, differed significantly from strains MIT-13 and SES-3, the previously described arsenate-reducing isolates, which grew on nitrate but not on sulfate. In contrast, strain OREX-4 did not respire nitrate but grew on lactate, with either arsenate or sulfate serving as the electron acceptor, and even preferred arsenate. Both arsenate and sulfate reduction were inhibited by molybdate. Strain OREX-4, a gram-positive bacterium with a hexagonal S-layer on its cell wall, metabolized compounds commonly used by sulfate reducers. Scorodite (FeAsO42· H2O) an arsenate-containing mineral, provided micromolar concentrations of arsenate that supported cell growth. Physiologically and phylogenetically, strain OREX-4 was far-removed from strains MIT-13 and SES-3: strain OREX-4 grew on different electron donors and electron accepters, and fell within the gram-positive group of the Bacteria, whereas MIT-13 and SES-3 fell together in the ε-subdivision of the Proteobacteria. Together, these results suggest that organisms spread among diverse bacterial phyla can use arsenate as a terminal electron acceptor, and that dissimilatory arsenate reduction might occur in the sulfidogenic zone at arsenate concentrations of environmental interest. 16S rRNA sequence analysis indicated that strain OREX-4 is a new species of the genus Desulfotomaculum, and accordingly, the name Desulfotomaculum auripigmentum is proposed.

Original languageEnglish (US)
Pages (from-to)380-388
Number of pages9
JournalArchives of Microbiology
Issue number5
StatePublished - Oct 15 1997

All Science Journal Classification (ASJC) codes

  • Genetics
  • Molecular Biology
  • Biochemistry
  • Microbiology


  • Arsenate reduction
  • Desulfotomaculum
  • Sulfate reduction


Dive into the research topics of 'Dissimilatory arsenate and sulfate reduction in Desulfotomaculum auripigmentum sp. nov.'. Together they form a unique fingerprint.

Cite this