Open AccessAssimilation of benzene carbon through multiple trophic levels traced by different stable isotope probing methodologies
Author(s) -
Bastida Felipe,
Jechalke Sven,
Bombach Petra,
Franchini Alessandro G.,
Seifert Jana,
von Bergen Martin,
Vogt Carsten,
Richnow Hans H.
Publication year - 2011
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2011.01118.x
Subject(s) - biology , trophic level , isotopes of carbon , assimilation (phonology) , isotope analysis , stable isotope ratio , isotope , carbon fibers , carbon assimilation , ecology , environmental chemistry , biochemistry , total organic carbon , photosynthesis , chemistry , philosophy , linguistics , physics , materials science , quantum mechanics , composite number , composite material
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 12 C‐ and [ 13 C 6 ]‐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 13 C‐benzene‐incubated biofilm. A higher 13 C‐enrichment was observed in TLFAs, indicative of Gram‐negative bacteria than for Gram‐positive. Fatty acid indicators of eukaryotes showed significant 13 C‐incorporation, but to a lower extent than bacterial indicators. Fatty acids extracted from larvae feeding on 13 C‐biofilm reached an isotopic ratio of 1.55 at.%, illustrating that the larvae feed, to some extent, on labelled biomass. No 13 C‐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.