Consulta: creatorFacets:"Niemann, Helge"
Registros recuperados: 3
Data/hora: 02/06/2024 00:44:59

Microbial methane oxidation and sulfate reduction at cold seeps of the deep Eastern Mediterranean Sea
Provedor de dados: 5
Autores: Omoregie, Enoma O.; Niemann, Helge; Mastalerz, Vincent; De Lange, Gert J.; Stadnitskaia, Alina; Mascle, Jean; Foucher, Jean-paul; Boetius, Antje.
The Eastern Mediterranean hosts a variety of active cold seep systems, such as gas chimneys, mud volcanoes and pockmarks, in water depths of 500 to 3200 m. As part of the NAUTINIL expedition in 2003, the sediments of cold seeps on the Nile Deep Sea Fan (NDSF) were sampled for the first time for biogeochemical and microbiological analyses. Here we compare rates of the anaerobic oxidation of methane (AOM) and sulfate reduction (SR) as well as the microbial community structure of a variety of cold seep systems including mud volcanoes, pockmarks and brine seeps. Our results revealed strong differences in microbial activity among the different seep systems of the Eastern, Central and Western provinces of the NDSF, as well as the Olimpi field (Central...
Tipo: Text
Palavras-chave: Methane oxidation; Sulfate reduction; Archaea; Cold seeps; Mud volcano; Pockmarks; Nile Deep Sea Fan.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11087/7910.pdf

The Impact of Methane on Microbial Communities at Marine Arctic Gas Hydrate Bearing Sediment
Provedor de dados: 5
Autores: Carrier, Vincent; Svenning, Mette M.; Grundger, Friederike; Niemann, Helge; Dessandier, Pierre-antoine; Panieri, Giuliana; Kalenitchenko, Dimitri.
Cold seeps are characterized by high biomass, which is supported by the microbial oxidation of the available methane by capable microorganisms. The carbon is subsequently transferred to higher trophic levels. South of Svalbard, five geological mounds shaped by the formation of methane gas hydrates, have been recently located. Methane gas seeping activity has been observed on four of them, and flares were primarily concentrated at their summits. At three of these mounds, and along a distance gradient from their summit to their outskirt, we investigated the eukaryotic and prokaryotic biodiversity linked to 16S and 18S rDNA. Here we show that local methane seepage and other environmental conditions did affect the microbial community structure and composition....
Tipo: Text
Palavras-chave: Arctic; Methane seeps; Prokaryotes; Methanotrophs; ANME; Sulfate-reducing bacteria; Eukaryotes; Foraminifera.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00667/77893/80077.pdf

Diversity and abundance of aerobic and anaerobic methane oxidizers at the Haakon Mosby mud volcano, Barents Sea
Provedor de dados: 5
Autores: Losekann, Tina; Knittel, Katrin; Nadalig, Thierry; Fuchs, Bernhard; Niemann, Helge; Boetius, Antje; Amann, Rudolf.
Submarine mud volcanoes are formed by expulsions of mud, fluids, and gases from deeply buried subsurface sources. They are highly reduced benthic habitats and often associated with intensive methane seepage. In this study, the microbial diversity and community structure in methane-rich sediments of the Haakon Mosby Mud Volcano (HMMV) were investigated by comparative sequence analysis of 16S rRNA genes and fluorescence in situ hybridization. In the active volcano center, which has a diameter of about 500 m, the main methane-consuming process was bacterial aerobic oxidation. In this zone, aerobic methanotrophs belonging to three bacterial clades closely affiliated with Methylobacter and Methylophaga species accounted for 56% +/- 8% of total cells. In...
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2617.pdf