Relative abundance and diversity of bacterial methanotrophs at the oxic-anoxic interface of the Congo deep-sea fan
|Author(s)||Bessette Sandrine1, 2, 3, Moalic Yann1, 2, 3, Gautey Sebastien1, 2, 3, Lesongeur Francoise1, 2, 3, Godfroy Anne1, 2, 3, Toffin Laurent1, 2, 3|
|Affiliation(s)||1 : IFREMER, Ctr Bretagne,Inst Carnot Ifremer EDROME, Lab Microbiol Environm Extremes, UMR 6197,REM EEP, F-29280 Plouzane, France.
2 : Univ Bretagne Occidentale, Inst Univ Europeen Mer, Lab Microbiol Environm Extremes, UMR 6197, Plouzane, France.
3 : CNRS, La Microbiol Environm Extremes, UMR 6197, Technopole Brest Iroise, Plouzane, France.
|Source||Frontiers In Microbiology (1664-302X) (Frontiers Media Sa), 2017-04 , Vol. 8 , N. 715 , P. 1-16|
|WOS© Times Cited||9|
|Keyword(s)||aerobic methane-oxidizing bacteria, pmoA, organic-rich sediment, methane seeps, Congo deep-sea fan|
Sitting at ~5 000 m water depth on the Congo-Angola margin and ~ 760 km offshore of the West African coast, the recent lobe complex of the Congo deep-sea fan receives large amounts of fluvial sediments (3-5% organic carbon). This organic-rich sedimentation area harbors habitats with chemosynthetic communities similar to those of cold seeps. In this study, we investigated relative abundance, diversity and distribution of aerobic methane-oxidizing bacteria (MOB) communities at the oxic-anoxic interface of sedimentary habitats by using fluorescence in situ hybridization and comparative sequence analysis of particulate mono-oxygenase (pmoA) genes. Our findings revealed that sedimentary habitats of the recent lobe complex hosted type I and type II MOB cells and comparisons of pmoA community compositions showed variations among the different organic-rich habitats. Furthermore, the pmoA lineages were taxonomically more diverse compared to methane seep environments and were related to those found at cold seeps. Surprisingly, MOB phylogenetic lineages typical of terrestrial environments were observed at such water depth. In contrast, MOB cells or pmoA sequences were not detected at the previous lobe complex that is disconnected from the Congo River inputs.