Anaerobic benzene degradation by Gram-positive sulfate-reducing bacteria

Nidal Abu Laban, Draženka Selesi, Carsten Jobelius, Rainer U. Meckenstock

Research output: Contribution to journalArticlepeer-review

87 Scopus citations

Abstract

Despite its high chemical stability, benzene is known to be biodegradable with various electron acceptors under anaerobic conditions. However, our understanding of the initial activation reaction and the responsible prokaryotes is limited. In the present study, we enriched a bacterial culture that oxidizes benzene to carbon dioxide under sulfate-reducing conditions. Community analysis using terminal restriction fragment length polymorphism, 16S rRNA gene sequencing and FISH revealed 95% dominance of one phylotype that is affiliated to the Gram-positive bacterial genus Pelotomaculum showing that sulfate-reducing Gram-positive bacteria are involved in anaerobic benzene degradation. In order to get indications of the initial activation mechanism, we tested the substrate utilization, performed cometabolism tests and screened for putative metabolites. Phenol, toluene, and benzoate could not be utilized as alternative carbon sources by the benzene-degrading culture. Cometabolic degradation experiments resulted in retarded rates of benzene degradation in the presence of phenol whereas toluene had no effect on benzene metabolism. Phenol, 2-hydroxybenzoate, 4-hydroxybenzoate, and benzoate were identified as putative metabolites in the enrichment culture. However, hydroxylated aromatics were shown to be formed abiotically. Thus, the finding of benzoate as an intermediate compound supports a direct carboxylation of benzene as the initial activation mechanism but additional reactions leading to its formation cannot be excluded definitely.

Original languageEnglish
Pages (from-to)300-311
Number of pages12
JournalFEMS Microbiology Ecology
Volume68
Issue number3
DOIs
StatePublished - Jun 2009
Externally publishedYes

Keywords

  • Benzene
  • Gram-positive bacteria
  • Sulfate reduction

Fingerprint

Dive into the research topics of 'Anaerobic benzene degradation by Gram-positive sulfate-reducing bacteria'. Together they form a unique fingerprint.

Cite this