Stable isotope fractionation of γ-Hexachlorocyclohexane (Lindane) during reductive dechlorination by two strains of sulfate-reducing bacteria
2009 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 9, 3155-3161 p.Article in journal (Refereed) Published
Carbon isotope fractionation factors were determined with the dichloro elimination of γ-hexachlorocyclohexane (γ-HCH) by the sulfate-reducing bacteria Desulfococcus multivorans DSM 2059 and Desulfovibrio gigas DSM 1382. Both strains are known for cometabolic HCH dechlorination. Degradation experiments with γ-HCH in concentrations of 22−25 μM were carried out using benzoate (for D. multivorans) and lactate (for D. gigas) as electron donors, respectively. γ-HCH was dechlorinated by both bacterial strains within four weeks, and the metabolites γ-3,4,5,6-tetrachlorocyclohexene (γ-TCCH), chlorobenzene (CB), and benzene were formed. The carbon isotope fractionation of γ-HCH dechlorination was quantified by the Rayleigh model, using a bulk enrichment factor (εC) of −3.9 ± 0.6 for D. gigas and −3.4 ± 0.5 for D. multivorans, which correspond to apparent kinetic isotope effect (AKIEC) values of 1.023 ± 0.004 or 1.02 ± 0.003 for stepwise Cl−C bond cleavage. The extent and range of isotope fractionation suggest that γ-HCH dechlorination can be monitored in anoxic environments by compound-specific isotope analysis (CSIA).
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2009. Vol. 43, no 9, 3155-3161 p.
IdentifiersURN: urn:nbn:se:umu:diva-25407DOI: 10.1021/es801284mOAI: oai:DiVA.org:umu-25407DiVA: diva2:231683