Hydrogen thresholds and steady-state concentrations associated with microbial arsenate respiration
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Hydrogen thresholds and steady-state concentrations associated with microbial arsenate respiration. / Heimann, Axel C.; Blodau, Christian; Postma, Dieke; Larsen, Flemming; Viet, Pham H.; Nhan, Pham Q.; Jessen, Søren; Duc, Mai T.; Hue, Nguyen T M; Jakobsen, Rasmus.
I: Environmental Science & Technology (Washington), Bind 41, Nr. 7, 2007, s. 2311-2317.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Hydrogen thresholds and steady-state concentrations associated with microbial arsenate respiration
AU - Heimann, Axel C.
AU - Blodau, Christian
AU - Postma, Dieke
AU - Larsen, Flemming
AU - Viet, Pham H.
AU - Nhan, Pham Q.
AU - Jessen, Søren
AU - Duc, Mai T.
AU - Hue, Nguyen T M
AU - Jakobsen, Rasmus
PY - 2007
Y1 - 2007
N2 - H2 thresholds for microbial respiration of arsenate (As(V)) were investigated in a pure culture of Sulfurospirillum arsenophilum. H2 was consumed to threshold concentrations of 0.03-0.09 nmol/L with As(V) as terminal electron acceptor, allowing for a Gibbs free-energy yield of 36-41 kJ per mol of reaction. These thresholds are among the lowest measured for anaerobic respirers and fall into the range of denitrifiers or Fe(III)-reducers. In sediments from an arsenic-contaminated aquifer in the Red River flood plain, Vietnam, H2 levels decreased to 0.4-2 nmol/L when As(V) was added under anoxic conditions. When As(V) was depleted, H2 concentrations rebounded by a factor of 10, a level similar to that observed in arsenic-free controls. The sediment-associated microbial population completely reduced millimolar levels of As(V) to arsenite (As(III)) within a few days. The rate of As(V)-reduction was essentially the same in sediments amended with a pure culture of S. arsenophilum. These findings together with a review of observed H2 threshold and steady-state values suggest that microbial As(V)-respirers have a competitive advantage over several other anaerobic respirers through their ability to thrive at low H2 levels.
AB - H2 thresholds for microbial respiration of arsenate (As(V)) were investigated in a pure culture of Sulfurospirillum arsenophilum. H2 was consumed to threshold concentrations of 0.03-0.09 nmol/L with As(V) as terminal electron acceptor, allowing for a Gibbs free-energy yield of 36-41 kJ per mol of reaction. These thresholds are among the lowest measured for anaerobic respirers and fall into the range of denitrifiers or Fe(III)-reducers. In sediments from an arsenic-contaminated aquifer in the Red River flood plain, Vietnam, H2 levels decreased to 0.4-2 nmol/L when As(V) was added under anoxic conditions. When As(V) was depleted, H2 concentrations rebounded by a factor of 10, a level similar to that observed in arsenic-free controls. The sediment-associated microbial population completely reduced millimolar levels of As(V) to arsenite (As(III)) within a few days. The rate of As(V)-reduction was essentially the same in sediments amended with a pure culture of S. arsenophilum. These findings together with a review of observed H2 threshold and steady-state values suggest that microbial As(V)-respirers have a competitive advantage over several other anaerobic respirers through their ability to thrive at low H2 levels.
U2 - 10.1021/es062067d
DO - 10.1021/es062067d
M3 - Journal article
C2 - 17438780
AN - SCOPUS:34247098545
VL - 41
SP - 2311
EP - 2317
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 7
ER -
ID: 173937912