Loading…

Microbial communities from Arctic marine sedimentsrespond slowly to methane addition duringex situenrichments

Anaerobic methanotrophic archaea (ANME) consume methane in marine sediments, limiting its release to the water column, but their responses to changes in methane and sulfate supplies remain poorly constrained. To address how methane exposure may affect microbial communities and methane‐ and sulfur‐cy...

Full description

Saved in:
Bibliographic Details
Published in:Environmental microbiology 2019
Main Authors: Klasek, Scott, Torres, Martha, Bartlett, Douglas H, Tyler, Madeline, Hong, Wei-Li, Colwell, Frederick
Format: Article
Language:English
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Anaerobic methanotrophic archaea (ANME) consume methane in marine sediments, limiting its release to the water column, but their responses to changes in methane and sulfate supplies remain poorly constrained. To address how methane exposure may affect microbial communities and methane‐ and sulfur‐cycling gene abundances in Arctic marine sediments, we collected sediments from offshore Svalbard that represent geochemical horizons where anaerobic methanotrophy is expected to be active, previously active, and long‐inactive based on reaction‐transport biogeochemical modelling of porewater sulfate profiles. Sediment slurries were incubated at in situ temperature and pressure with different added methane concentrations. Sediments from an active area of seepage began to reduce sulfate in a methane‐dependent manner within months, preceding increased relative abundances of anaerobic methanotrophs ANME‐1 within communities. In previously active and long‐inactive sediments, sulfur‐cycling Deltaproteobacteria became more dominant after 30 days, though these communities showed no evidence of methanotrophy after nearly 8 months of enrichment. Overall, enrichment conditions, but not methane, broadly altered microbial community structure across different enrichment times and sediment types. These results suggest that active ANME populations may require years to develop, and consequently microbial community composition may affect methanotrophic responses to potential large‐scale seafloor methane releases in ways that provide insight for future modelling studies.
ISSN:1462-2920
1462-2912
1462-2920
DOI:10.1111/1462-2920.14895