Desulfitobacterium aromaticivorans sp. nov. and Geobacter toluenoxydans sp. nov., iron-reducing bacteria capable of anaerobic degradation of monoaromatic hydrocarbons

Int J Syst Evol Microbiol. 2010 Mar;60(Pt 3):686-695. doi: 10.1099/ijs.0.003525-0. Epub 2009 Aug 5.

Abstract

Dissimilatory iron reduction plays a significant role in subsurface environments. Currently, it is assumed that members of the genus Geobacter constitute the majority of the iron-reducing micro-organisms that oxidize aromatic compounds in contaminated subsurface environments. Here, we report the isolation of two phylogenetically distinct pure cultures of iron-reducing degraders of monoaromatic hydrocarbons, strain TMJ1(T), which belongs to the genus Geobacter within the Deltaproteobacteria, and strain UKTL(T), belonging to the genus Desulfitobacterium within the Clostridia. Both strains utilize a wide range of substrates as carbon and energy sources, including the aromatic compounds toluene, phenol and p-cresol. Additionally, strain UKTL(T) utilizes o-xylene and TMJ1(T) utilizes m-cresol. Anaerobic degradation of toluene in both strains and o-xylene in strain UKTL(T) is initiated by activation with fumarate addition to the methyl group. The genomic DNA G+C contents of strains TMJ1(T) and UKTL(T) are 54.4 and 47.7 mol%, respectively. Based on a detailed physiological characterization and phylogenetic analysis of the 16S rRNA genes of both strains, we propose the names Desulfitobacterium aromaticivorans sp. nov. (type strain UKTL(T) =DSM 19510(T) =JCM 15765(T)) and Geobacter toluenoxydans sp. nov. (type strain TMJ1(T) =DSM 19350(T) =JCM 15764(T)) to accommodate these strains. To the best of our knowledge, strain UKTL(T) is the first described spore-forming, iron-reducing bacterium that can degrade aromatic hydrocarbons.

MeSH terms

  • Betaproteobacteria / classification*
  • Betaproteobacteria / genetics
  • Betaproteobacteria / isolation & purification*
  • Betaproteobacteria / metabolism
  • Cellulose / metabolism*
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • Fatty Acids / chemistry
  • Fatty Acids / metabolism
  • Molecular Sequence Data
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics

Substances

  • DNA, Bacterial
  • DNA, Ribosomal
  • Fatty Acids
  • RNA, Ribosomal, 16S
  • Cellulose

Associated data

  • GENBANK/EU711071
  • GENBANK/EU711072