Document Detail


Microbial methane turnover at Marmara Sea cold seeps: a combined 16S rRNA and lipid biomarker investigation.
MedLine Citation:
PMID:  23205581     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Lipid biomarkers and their stable carbon isotopic composition, as well as 16S rRNA gene sequences, were investigated in sediment cores from active seepage zones in the Sea of Marmara (Turkey) located on the active North Anatolian Fault, to assess processes associated with methane turnover by indigenous microbial communities. Diagnostic (13) C-depleted archaeal lipids of anaerobic methane oxidizers were only found in one core from the South of Çinarcik Basin and consist mainly of archaeol, sn-2 hydroxyarchaeol and various unsaturated pentamethylicosenes. Concurrently, abundant fatty acids (FAs) and a substantial amount of monoalkylglycerolethers (MAGEs), assigned to sulphate-reducing bacteria, were detected with strong (13) C-depletions. Both microbial lipids and their δ(13) C values suggest that anaerobic oxidation of methane with sulphate reduction (AOM/SR) occurs, specially in the 10- to 12-cm depth interval. Lipid biomarker results accompanied by 16S rRNA-based microbial diversity analyses showed that ANME-2 (ANME-2a and -2c) archaea and Desulfosarcina/Desulfococcus and Desulfobulbus deltaproteobacterial clades are the major AOM assemblages, which indicate a shallow AOM community at high methane flux. Apart from the typical AOM lipid biomarker pattern, a (13) C-depleted diunsaturated hydrocarbon, identified as 7,14-tricosadiene, occurred in the inferred maximum AOM interval at 10-12 cm depth. Its isotopic fingerprint implies that its microbial precursor occurs in close association with the AOM communities. Interestingly, the presence of 7,14-tricosadiene coincides with the presence of the so-far uncultured bacterial Candidate Division JS1, often detected in AOM areas. We propose the hypothesis that the JS1 bacterial group could be the potential source of (13) C-depleted tricosadiene. Future testing of this hypothesis is essential to fully determine the role of this bacterial group in AOM.
Authors:
N Chevalier; I Bouloubassi; D Birgel; M-H Taphanel; P López-García
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-12-4
Journal Detail:
Title:  Geobiology     Volume:  -     ISSN:  1472-4669     ISO Abbreviation:  Geobiology     Publication Date:  2012 Dec 
Date Detail:
Created Date:  2012-12-4     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101185472     Medline TA:  Geobiology     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
© 2012 Blackwell Publishing Ltd.
Affiliation:
Laboratoire d'Océanographie et du Climat, Expérimentation et Approches Numériques (LOCEAN), CNRS UMR 7159, IPSL, Université Pierre et Marie Curie, Paris Cedex, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Heart Rate Variability and Red Cell Distribution Width in Patients with Systolic Left Heart Failure.
Next Document:  H+/K+-ATPase inhibitors: a patent review.