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

• Published in: Environmental microbiology Vol. 6; no. 6; pp. 646 - 650
• Main Authors: Luijten, Maurice L. G. C., Roelofsen, Wim, Langenhoff, Alette A. M., Schraa, Gosse, Stams, Alfons J. M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.06.2004
• Subjects: Bacteria - metabolism; Biodegradation, Environmental; Dehalobacter restrictus; Geologic Sediments - microbiology; Hydrogen - metabolism; Netherlands; Soil Pollutants - metabolism; Sulfurospirillum halorespirans; Tetrachloroethylene - metabolism; Trichloroethylene - metabolism; Netherlands
• ISSN: 1462-2912; 1462-2920
• DOI: 10.1111/j.1462-2920.2004.00608.x

Summary Halorespiring microorganisms are not only able to oxidize organic electron donors such as formate, acetate, pyruvate and lactate, but also H2. Because these microorganisms have a high affinity for H2, this may be the most important electron donor for halorespiration in the environment. We have studied the role of H2‐threshold concentrations in pure halorespiring cultures and compared them with mixed cultures and field data. We have found H2‐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 H2 concentrations of below 1 nM at a polluted site. However, for the reduction of lower chlorinated ethenes a higher H2 concentration is required. This indicates that the measured H2 concentration in situ can be an indicator of the extent of anaerobic reductive dechlorination.