Geothrix fermentans gen. nov., sp. nov., a novel Fe(III)-reducing bacterium from a hydrocarbon-contaminated aquifer

Int J Syst Bacteriol. 1999 Oct;49 Pt 4:1615-22. doi: 10.1099/00207713-49-4-1615.


In an attempt to understand better the micro-organisms involved in anaerobic degradation of aromatic hydrocarbons in the Fe(III)-reducing zone of petroleum-contaminated aquifers, Fe(III)-reducing micro-organisms were isolated from contaminated aquifer material that had been adapted for rapid oxidation of toluene coupled to Fe(III) reduction. One of these organisms, strain H-5T, was enriched and isolated on acetate/Fe(III) medium. Strain H-5T is a Gram-negative strict anaerobe that grows with various simple organic acids such as acetate, propionate, lactate and fumarate as alternative electron donors with Fe(III) as the electron acceptor. In addition, strain H-5T also oxidizes long-chain fatty acids such as palmitate with Fe(III) as the sole electron acceptor. Strain H-5T can also grow by fermentation of citrate or fumarate in the absence of an alternative electron acceptor. The primary end-products of citrate fermentation are acetate and succinate. In addition to various forms of soluble and insoluble Fe(III), strain H-5T grows with nitrate, Mn(IV), fumarate and the humic acid analogue 2,6-anthraquinone disulfonate as alternative electron acceptors. As with other organisms that can oxidize organic compounds completely with the reduction of Fe(III), cell suspensions of strain H-5T have absorbance maxima indicative of a c-type cytochrome(s). It is proposed that strain H-5T represents a novel genus in the Holophaga-Acidobacterium phylum and that it should be named Geothrix fermentans sp. nov., gen. nov.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biodegradation, Environmental
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • Ferric Compounds / metabolism*
  • Geologic Sediments / microbiology*
  • Gram-Negative Anaerobic Bacteria / classification*
  • Gram-Negative Anaerobic Bacteria / isolation & purification
  • Gram-Negative Anaerobic Bacteria / metabolism
  • Gram-Negative Anaerobic Bacteria / physiology
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Petroleum / metabolism*
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Water Microbiology
  • Water Pollutants, Chemical / metabolism*
  • Water Supply*


  • DNA, Bacterial
  • DNA, Ribosomal
  • Ferric Compounds
  • Petroleum
  • RNA, Ribosomal, 16S
  • Water Pollutants, Chemical

Associated data

  • GENBANK/U41563