Page 130 - Microbial methane cycling in a warming world From biosphere to atmosphere Michiel H in t Zandt

Chapter 5. Early Holocene carbon storage and microbial activity in North Sea peats Conclusions and perspectives
Methane concentrations were generally low with locally high concentrations. The source of methane remains unknown. Basal-peat deposits are globally widespread beneath land and ocean surfaces and function as a store of CH4 that, in the event of physical disturbance, has been shown to be at risk of being released into the atmosphere. Large carbon stores in the presence of methanogenic bacteria in the absence of methanotrophs hold the potential for this material to be metabolised into methane gas, under different environmental conditions. The results of this study are a stepping stone towards assessing the contribution of basal-peat deposits to regional and global carbon and methane budgets. Microbial community structure analysis using 16S rRNA gene-based sequencing techniques and activity assays indicated the absence of a CH4 biofilter. This knowledge contributes to better understanding the roles and feedbacks of microorganisms in CH4 storage and cycling.
Acknowledgements
General. We thank Theo van Alen and Sihle Patience Ginindza for technical assistance. We thank the Royal Netherlands Institute for Sea Research (NIOZ) and particularly Gert-Jan Reichhart, who was instrumental in organizing the two cruises. We thank the captain, and the entire crew of the R/V Pelagia for enabling the success of the two sampling campaigns. Funding. This work was supported by the Netherlands Organisation for Scientific Research through the Soehngen Institute of Anaerobic Microbiology (SIAM) Gravitation Grant [grant number 024.002.002] and the Netherlands Earth System Science Center Gravitation Grant [grant number 024.002.001]. MSMJ was supported by ERC AG Ecomom 339880, and MSMJ and CPS were supported by ERC SyG Marix 854088.
Author contributions. Conceptualization: TL MitZ HD. Analysis: TL MitZ NvdP FB MH PvdV TdG ZvA. Funding acquisition: FB MH HN MJ CW HD. Methodology: TL MitZ NvdP OM CS HD. Writing – original draft: TL MitZ CW HD. Writing – review and editing: TL MitZ.
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