Open AccessHydrogen and carbon isotope fractionation during degradation of chloromethane by methylotrophic bacteria
Author(s) -
Nadalig Thierry,
Greule Markus,
Bringel Françoise,
Vuilleumier Stéphane,
Keppler Frank
Publication year - 2013
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.124
Subject(s) - chloromethane , chemistry , environmental chemistry , isotope analysis , fractionation , stable isotope ratio , isotope fractionation , isotopes of carbon , hydrogen , organic chemistry , total organic carbon , biology , ecology , catalysis , physics , quantum mechanics
Chloromethane ( CH 3 Cl ) is a widely studied volatile halocarbon involved in the destruction of ozone in the stratosphere. Nevertheless, its global budget still remains debated. Stable isotope analysis is a powerful tool to constrain fluxes of chloromethane between various environmental compartments which involve a multiplicity of sources and sinks, and both biotic and abiotic processes. In this study, we measured hydrogen and carbon isotope fractionation of the remaining untransformed chloromethane following its degradation by methylotrophic bacterial strains Methylobacterium extorquens CM 4 and Hyphomicrobium sp. MC 1, which belong to different genera but both use the cmu pathway, the only pathway for bacterial degradation of chloromethane characterized so far. Hydrogen isotope fractionation for degradation of chloromethane was determined for the first time, and yielded enrichment factors (ε) of −29‰ and −27‰ for strains CM 4 and MC 1, respectively. In agreement with previous studies, enrichment in 13 C of untransformed CH 3 Cl was also observed, and similar isotope enrichment factors (ε) of −41‰ and −38‰ were obtained for degradation of chloromethane by strains CM 4 and MC 1, respectively. These combined hydrogen and carbon isotopic data for bacterial degradation of chloromethane will contribute to refine models of the global atmospheric budget of chloromethane.