Editor: Max Häggblom
Assimilation of benzene carbon through multiple trophic levels traced by different stable isotope probing methodologies
Article first published online: 20 MAY 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Ecology
Volume 77, Issue 2, pages 357–369, August 2011
How to Cite
Bastida, F., Jechalke, S., Bombach, P., Franchini, A. G., Seifert, J., von Bergen, M., Vogt, C. and Richnow, H. H. (2011), Assimilation of benzene carbon through multiple trophic levels traced by different stable isotope probing methodologies. FEMS Microbiology Ecology, 77: 357–369. doi: 10.1111/j.1574-6941.2011.01118.x
Present addresses: Sven Jechalke, Federal Research Center for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute (JKI), Braunschweig, Germany. A.G. Franchini, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Federal Institute of Technology (ETH), Zürich, Switzerland.
- Issue published online: 11 JUL 2011
- Article first published online: 20 MAY 2011
- Accepted manuscript online: 21 APR 2011 06:52AM EST
- Received 3 January 2011; revised 12 April 2011; accepted 13 April 2011., Final version published online 20 May 2011.
- stable isotope probing;
- fatty acid-SIP;
- amino acid-SIP;
- benzene degradation;
- food web
The flow of benzene carbon along a food chain consisting of bacteria and eukaryotes, including larvae (Diptera: Chironomidae), was evaluated by total lipid fatty acids (TLFAs)-, amino acid- and protein-stable isotope probing (SIP). A coconut-fibre textile, colonized by a benzene-degrading biofilm, was sampled in a system established for the remediation of benzene, toluene, ethylbenzene and xylenes (BTEX)-polluted groundwater and incubated with 12C- and [13C6]-benzene (>99 at.%) in a batch-scale experiment for 2–8 days. After 8 days, Chironomus sp. larvae were added to study carbon flow to higher trophic levels. Gas chromatography-combustion-isotope ratio monitoring mass spectrometry of TLFA showed increased isotope ratios in the 13C-benzene-incubated biofilm. A higher 13C-enrichment was observed in TLFAs, indicative of Gram-negative bacteria than for Gram-positive. Fatty acid indicators of eukaryotes showed significant 13C-incorporation, but to a lower extent than bacterial indicators. Fatty acids extracted from larvae feeding on 13C-biofilm reached an isotopic ratio of 1.55 at.%, illustrating that the larvae feed, to some extent, on labelled biomass. No 13C-incorporation was detectable in larval proteins after their separation by sodium-dodecyl sulphate-polyacrylamide gel electrophoresis and analysis by nano-liquid-chromatography-mass spectrometry. The flow of benzene-derived carbon could be traced in a food web consisting of bacteria and eukaryotes.