Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.est.5c14089
Licence creative commons licence
Title (Primary) Isotopic fractionation and masking effects during biotransformation of chlorinated ethanes
Author Phillips, E.; De Vera, J.; Kümmel, S. ORCID logo ; Bulka, O.; Chen, W.; Edwards, E.; Nijenhuis, I.; Gehre, M. ORCID logo ; Sherwood Lollar, B.
Source Titel Environmental Science & Technology
Year 2026
Department TECH
Volume 60
Issue 22
Page From 15940
Page To 15951
Language englisch
Topic T7 Bioeconomy
Supplements Supplement 1
Keywords CSIA; contaminant hydrogeology; biotransformation; reductive dehalogenation; enzyme kinetics
Abstract Chlorinated ethanes, such as 1,1,1-trichloroethane (1,1,1-TCA) and 1,1-dichloroethane (1,1-DCA), are common groundwater contaminants that undergo abiotic and biotic transformation, although the specific mechanisms remain unresolved. Compound-specific isotope analysis (CSIA) can provide insight into transformation mechanisms, but its application to chlorinated ethanes has been limited compared to the extensive literature on chlorinated ethenes. This study presents the first dual-element stable isotope (carbon and chlorine) analysis of 1,1,1-TCA and 1,1-DCA biotransformation by an enriched microbial culture commonly used in field remediation. The isotopic fractionation (ε) values for carbon and chlorine are −5.8 ± 0.8‰ and −2.8 ± 0.3‰, respectively, for 1,1,1-TCA and are −8.9 ± 1.0‰ and −4.3 ± 0.5‰, respectively, for 1,1-DCA. Dual-isotope plots produced slopes (ΛCl/C) of 2.1 ± 0.1 for 1,1,1-TCA and 2.1 ± 0.2 for 1,1-DCA, consistent with previously reported ΛCl/C values for abiotic transformation, despite significant differences in ε values, suggesting a masking effect that suppresses carbon and chlorine isotopic fractionation. Significantly, chlorine isotope values in the formed products are more enriched than the substrates, which may be diagnostic for masking effects in chlorinated organic compounds.
Phillips, E., De Vera, J., Kümmel, S., Bulka, O., Chen, W., Edwards, E., Nijenhuis, I., Gehre, M., Sherwood Lollar, B. (2026):
Isotopic fractionation and masking effects during biotransformation of chlorinated ethanes
Environ. Sci. Technol. 60 (22), 15940 - 15951
10.1021/acs.est.5c14089