Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz.

Francisco J R C Coelho,Patrícia M Domingues,Adelaide Almeida,António Louvado,Newton C M Gomes,Daniel F R Cleary,Ângela Cunha,Marina Ferreira,Marina R Cunha

doi:10.1038/srep35272

Francisco J R C Coelho, Patrícia M Domingues + Show 7 more

Open Access

https://doi.org/10.1038/srep35272

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Journal: Scientific Reports	Publication Date: Oct 20, 2016
Citations: 22	License type: CC BY 4.0

Affiliation: University of Aveiro

Abstract

The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults.

Highlights

Structural and functional composition, in particular in regard to microeukaryotes - the first-level consumers
We focused our analysis on Bacteria, assuming their high abundance and functional relevance in the process of methane oxidation in surface sediments of mud volcanoes (MVs) seeps[14,15]
Along the first axis of variation, sample 308 is clearly separated from the rest of the samples. This sample was collected in Porto MV, an active MV located on the AWGC

Summary

Introduction

Structural and functional composition, in particular in regard to microeukaryotes - the first-level consumers. A 16S and 18S-based pyrosequencing approach was applied to investigate prokaryotic and microeukaryotic communities present in the surface sediments of deep-sea MVs associated with strike-slip faults in the SWIM. We focused our analysis on Bacteria, assuming their high abundance and functional relevance in the process of methane oxidation in surface sediments of MV seeps[14,15]. Our main objectives were to characterize the bacterial and microeukaryotic communities in MVs with different seepage regimes and to assess possible relationships between different microbial groups. This work can contribute to the understanding of microbial communities and their potential impact on processes in the MV environment

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Discussion

Conclusion