TY - JOUR
T1 - Dual (C, H) isotope fractionation in anaerobic low molecular weight (poly)aromatic hydrocarbon (PAH) degradation
T2 - Potential for field studies and mechanistic implications
AU - Bergmann, Franz D.
AU - Abu Laban, Nidal M.F.H.
AU - Meyer, Armin H.
AU - Elsner, Martin
AU - Meckenstock, Rainer U.
PY - 2011/8/15
Y1 - 2011/8/15
N2 - Anaerobic polycyclic aromatic hydrocarbon (PAH) degradation is a key process for natural attenuation of oil spills and contaminated aquifers. Assessments by stable isotope fractionation, however, have largely been limited to monoaromatic hydrocarbons. Here, we report on measured hydrogen isotope fractionation during strictly anaerobic degradation of the PAH naphthalene. Remarkable large hydrogen isotopic enrichment factors contrasted with much smaller values for carbon: ε H = -100‰ ± 15‰, ε C = -5.0‰ ± 1.0‰ (enrichment culture N47); ε H = -73‰ ± 11‰, ε C = -0.7‰ ± 0.3‰ (pure culture NaphS2). This reveals a considerable potential of hydrogen isotope analysis to assess anaerobic degradation of PAHs. Furthermore, we investigated the conclusiveness of dual isotope fractionation to characterize anaerobic aromatics degradation. C and H isotope fractionation during benzene degradation (ε C = -2.5‰ ± 0.2‰ ε H = -55‰ ± 4‰ (sulfate-reducing strain BPL); ε C = -3.0‰ ± 0.5‰ ε H = -56‰ ± 8‰ (iron-reducing strain BF)) resulted in dual isotope slopes (λ = 20 ± 2; 17 ± 1) similar to those reported for nitrate-reducers. This breaks apart the current picture that anaerobic benzene degradation by facultative anaerobes (denitrifiers) can be distinguished from that of strict anaerobes (sulfate-reducers, fermenters) based on the stable isotope enrichment factors.
AB - Anaerobic polycyclic aromatic hydrocarbon (PAH) degradation is a key process for natural attenuation of oil spills and contaminated aquifers. Assessments by stable isotope fractionation, however, have largely been limited to monoaromatic hydrocarbons. Here, we report on measured hydrogen isotope fractionation during strictly anaerobic degradation of the PAH naphthalene. Remarkable large hydrogen isotopic enrichment factors contrasted with much smaller values for carbon: ε H = -100‰ ± 15‰, ε C = -5.0‰ ± 1.0‰ (enrichment culture N47); ε H = -73‰ ± 11‰, ε C = -0.7‰ ± 0.3‰ (pure culture NaphS2). This reveals a considerable potential of hydrogen isotope analysis to assess anaerobic degradation of PAHs. Furthermore, we investigated the conclusiveness of dual isotope fractionation to characterize anaerobic aromatics degradation. C and H isotope fractionation during benzene degradation (ε C = -2.5‰ ± 0.2‰ ε H = -55‰ ± 4‰ (sulfate-reducing strain BPL); ε C = -3.0‰ ± 0.5‰ ε H = -56‰ ± 8‰ (iron-reducing strain BF)) resulted in dual isotope slopes (λ = 20 ± 2; 17 ± 1) similar to those reported for nitrate-reducers. This breaks apart the current picture that anaerobic benzene degradation by facultative anaerobes (denitrifiers) can be distinguished from that of strict anaerobes (sulfate-reducers, fermenters) based on the stable isotope enrichment factors.
UR - http://www.scopus.com/inward/record.url?scp=80051726732&partnerID=8YFLogxK
U2 - 10.1021/es201096j
DO - 10.1021/es201096j
M3 - Article
C2 - 21711028
AN - SCOPUS:80051726732
SN - 0013-936X
VL - 45
SP - 6947
EP - 6953
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 16
ER -