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Microbial community composition and biogeochemical processes in cold-water-coral carbonate mounds in the Gulf of Cadiz, on the Moroccan margin

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Publication date 2011
Author Templer S.P. Wehrmann L.M. Zhang Y. Vasconcelos C. and McKenzie J.A.,
Project Using New Geochemical and Nanotechnological Approach to Study Biomineralization in Microbiolites
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Original article (peer-reviewed)

Journal Marine Geology
Volume (Issue) 282
Page(s) 138 - 148
Title of proceedings Marine Geology
DOI 10.1016/j.margeo.2010.10.020


This study reports on the microbial community composition of Bacteria and Archaea in a cluster of carbonate mounds located in the Gulf of Cadiz on the Moroccan margin at water depths between 500 and 600 m amidst a field of mud volcanoes. Although nearly no live corals were observed on the mound surfaces, gravity cores examined from both Alpha and Beta Mound (MD 169 MiCROSYSTEMS cruise, cores MD08-3218 and MD08-3214, respectively) display a high number of cold-water coral fragments (scleractinians) throughout the cores. Molecular techniques, using taxonomic (16S rRNA gene PCR-DGGE) and functional (mcrA and dsrAB) gene markers, were applied to assess prokaryotic diversity. This was compared with the distribution of total cell counts and a novel approach of ATP-activity measurements to identify microbial activity hot spots during core sub-sampling. Despite broad similarities in the prokaryotic community at the two sites, some differences were observed at specific depth intervals, in correlation with differences in ATP activity. Alpha and Beta Mound showed evidence for the presence of a shallow sulfate–methane transition zone (SMTZ) with increased sulfate reduction rates indicating the presence of microbially mediated anaerobic oxidation of methane (AOM). The key marker gene for methanotrophy and methanogenesis (mcrA)