title: Characterization of phenol and cresol biodegradation by compound-specific stable isotope analysis.
abstract: Microbial degradation of phenol and cresols can occur under oxic and anoxic conditions by different degradation pathways. One recent technique to take insight into reaction mechanisms is compound-specific isotope analysis (CSIA). While enzymes and reaction mechanisms of several degradation pathways have been characterized in (bio)chemical studies, associated isotope fractionation patterns have been rarely reported, possibly due to constraints in current analytical methods. In this study, carbon enrichment factors and apparent kinetic isotope effects (AKIEc) of the initial steps of different aerobic and anaerobic phenol and cresols degradation pathways were analyzed by isotope ratio mass spectrometry connected with liquid chromatography (LC-IRMS). Significant isotope fractionation was detected for aerobic ring hydroxylation, anoxic side chain hydroxylation, and anoxic fumarate addition, while anoxic carboxylation reactions produced small and inconsistent fractionation. The results suggest that several microbial degradation pathways of phenol and cresols are detectable in the environment by CSIA.
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; Friedrich Schiller University Jena, Institute for Microbiology, Department of Applied and Ecological Microbiology, Jena, Germany.
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany.
authors.forename: Tetyana
authors.initials: T
authors.lastname: Gilevska
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; Friedrich Schiller University Jena, Faculty of Chemistry and Earth Science, Jena, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Wetzig
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany; University of Freiburg, Faculty of Biology, Schänzlestrasse 1, Freiburg, Germany.
authors.forename: Conrad
authors.initials: C
authors.lastname: Dorer
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany.
authors.forename: Hans-Hermann
authors.initials: HH
authors.lastname: Richnow
authors.affiliation: Helmholtz Centre for Environmental Research - UFZ, Department of Isotope Biogeochemistry, Leipzig, Germany. Electronic address: carsten.vogt@ufz.de.
authors.forename: Carsten
authors.initials: C
authors.lastname: Vogt
mesh_terms: D001673:Biodegradation, Environmental; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism; D005591:Chemical Fractionation / Q000379:methods; D003408:Cresols / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D010636:Phenols / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D003408:Cresols; D010636:Phenols
keywords: Benzylsuccinate synthase; Carbon isotope fractionation; LC-IRMS; Monooxygenase; p-Cresol methyl hydroxylase