Interconnectivity vs. isolation of prokaryotic communities in European deep-sea mud volcanoes

[摘要] During the past two decades, European cold seep ecosystems have attractedthe scientific interest and to date there are several studies which haveinvestigated the community structure and biodiversity of individual sites.In order to gain a better insight into the biology, biodiversity, andbiogeography of seep-associated microbial communities along Europe'scontinental margins, a comparative approach was applied in the present work.By exploiting the publicly available data on 16S rRNA gene sequencesretrieved from sediments of the Håkon Mosby mud volcano, Gulf of Cádizand the eastern Mediterranean mud volcanoes/pockmarks (Anaximander area andNile Fan), we investigated the prokaryotic biological components connectingthese geographically isolated systems. The construction of interactionnetworks for both archaeal and bacterial shared operational taxonomic units(OTUs) among the different sites, revealed the presence of persistent OTUs,which can be considered as "key-players". One archaeal OTU (HQ588641)belonging to the ANME-3 group and one δ-Proteobacteria (HQ588562)were found in all five investigated areas. Other Archaea OTUs shared betweenfour sites or less, belonged to the ANME-2c, -2a, MBG-D, -B andThaumarchaeota. All other shared Bacteria belonged to the δ- andγ-Proteobacteria, with the exception of one JS1 affiliate OTU. Thedistribution of the majority of the shared OTUs seems to be restricted incold seeps, mud volcanoes and other marine methane-rich environments.Although the investigated sites were connected through a small number ofOTUs, these microorganisms hold central ecophysiological roles in thesesediments, namely methane- and sulfur-mediated mineralization.

[学科分类] 地球化学与岩石