Characterization of anaerobic xylene biodegradation by two-dimensional isotope fractionation analysis
Article first published online: 29 SEP 2009
© 2009 Society for Applied Microbiology and Blackwell Publishing Ltd
Environmental Microbiology Reports
Volume 1, Issue 6, pages 535–544, December 2009
How to Cite
Herrmann, S., Vogt, C., Fischer, A., Kuppardt, A. and Richnow, H.-H. (2009), Characterization of anaerobic xylene biodegradation by two-dimensional isotope fractionation analysis. Environmental Microbiology Reports, 1: 535–544. doi: 10.1111/j.1758-2229.2009.00076.x
- Issue published online: 20 NOV 2009
- Article first published online: 29 SEP 2009
- Received 2 May, 2009; accepted 11 August, 2009.
We determined stable carbon and hydrogen isotope fractionation factors for anaerobic degradation of xylene isomers by several pure and mixed cultures. All cultures initiated xylene degradation by the addition of fumarate to a methyl moiety, as is known from the literature or verified by the presence of methylbenzylsuccinates as metabolic intermediates. Additionally, the A subunit of benzylsuccinate synthase (bssA) was identified in the majority of the cultures by bssA-targeted primers. Xylene degradation was always coupled to a significant carbon and hydrogen isotope fractionation. The values of the apparent kinetic isotope effect (AKIE) for carbon and hydrogen indicate that the cleavage of a carbon–hydrogen bond is an isotope-sensitive step during fumarate addition to xylene isomers. The slopes of the linear regression for hydrogen (Δδ2H) versus carbon (Δδ13C) discrimination (Λ = Δδ2H/Δδ13C ≈ εHbulk/εCbulk) ranged from 12 ± 4 to 29 ± 5 and were comparable to Λ values previously determined for anaerobic toluene degradation. The results suggest that combined carbon and hydrogen isotope fractionation analyses can be used to monitor anaerobic xylene degradation at contaminated sites.