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Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
Hydrogen threshold concentrations in pure cultures of halorespiring bacteria and at a site polluted with chlorinated
Maurice L G C Luijten1, Wim Roelofsen, Alette A M Langenhoff
1Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands. m.l.g.c.luijten@mep.tno.nl
Abstract:
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.
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