Potential activity of subglacial microbiota transported to anoxic river delta sediments

Cameron, K. A. , Stibal, M., Olsen, N. S., Mikkelsen, A. B., Elberling, B. and Jacobsen, C. S. (2017) Potential activity of subglacial microbiota transported to anoxic river delta sediments. Microbial Ecology, 74, pp. 6-9. (doi: 10.1007/s00248-016-0926-2) (PMID:28070677) (PMCID:PMC5486838)

Abstract

The Watson River drains a portion of the SW Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers of sediments within the river delta. A long-term (12-month) incubation experiment was established using Watson River delta sediment under anaerobic conditions, with and without CO2/H2 enrichment. Within CO2/H2-amended incubations, sulphate depletion and a shift in the microbial community to a 52% predominance of Desulfosporosinus meridiei by day 371 provides evidence for sulphate reduction. We found evidence of methanogenesis in CO2/H2-amended incubations within the first 5 months, with production rates of ~4 pmol g−1 d−1, which was likely performed by methanogenic Methanomicrobiales- and Methanosarcinales-related organisms. Later, a reduction in methane was observed to be paired with the depletion of sulphate, and we hypothesise that sulphate reduction out competed hydrogenotrophic methanogenesis. The structure and diversity of the original CO2/H2-amended incubation communities changed dramatically with a major shift in predominant community members and a decline in diversity and cell abundance. These results highlight the need for further investigations into the fate of subglacial microbiota within downstream environments.

• Item Type: Articles
• Additional Information: This research was funded by Danish Research Council grants FNU 10-085274 to CSJ and CENPERM DNRF100. It has additionally been supported by a Czech Science Foundation grant GACR 15-17346Y to MS.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cameron, Dr Karen
• Authors: Cameron, K. A., Stibal, M., Olsen, N. S., Mikkelsen, A. B., Elberling, B., and Jacobsen, C. S.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
• Journal Name: Microbial Ecology
• Publisher: Springer Verlag
• ISSN: 0095-3628
• ISSN (Online): 1432-184X
• Copyright Holders: Copyright © The Author(s) 2017
• First Published: First published in Microbial Ecology 74:6-9
• Publisher Policy: Reproduced under a Creative Commons license