Hydrogen threshold concentrations in pure cultures of halorespiring bacteria and at a site polluted with chlorinated ethenes

Environ Microbiol. 2004 Jun;6(6):646-50. doi: 10.1111/j.1462-2920.2004.00608.x.


Halorespiring microorganisms are not only able to oxidize organic electron donors such as formate, acetate, pyruvate and lactate, but also H(2). Because these microorganisms have a high affinity for H(2), this may be the most important electron donor for halorespiration in the environment. We have studied the role of H(2)-threshold concentrations in pure halorespiring cultures and compared them with mixed cultures and field data. We have found H(2)-threshold values between 0.05 and 0.08 nM for Sulfurospirillum halorespirans, S. multivorans and Dehalobacter restrictus under PCE-reducing and nitrate-reducing conditions. The reduction of PCE and TCE can proceed at H(2) concentrations of below 1 nM at a polluted site. However, for the reduction of lower chlorinated ethenes a higher H(2) concentration is required. This indicates that the measured H(2) concentration in situ can be an indicator of the extent of anaerobic reductive dechlorination.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / metabolism*
  • Biodegradation, Environmental
  • Geologic Sediments / microbiology*
  • Hydrogen / metabolism*
  • Netherlands
  • Soil Pollutants / metabolism
  • Tetrachloroethylene / metabolism
  • Trichloroethylene / metabolism


  • Soil Pollutants
  • Trichloroethylene
  • Hydrogen
  • Tetrachloroethylene