Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster E19

Microbial ecology of the subglacial East Skaftár lake in Vatnajökull glacier: new insights from metagenome sequencing.

Höfundar / Authors: Gregory K. Farrant (1), Pauline Vannier (1), Alexandra Klonowski (1), Eric Gaidos(2), Þorsteinn Þorsteinsson (3,4) and Viggó Þór Marteinsson (1,5)

Starfsvettvangur / Affiliations: 1. MATIS, Department of Research and Innovation, Reykjavík, Iceland; 2. Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, Hawaii, USA; 3. Science Institute, University of Iceland, Reykjavík, Iceland; 4. Icelandic Meteorological Office, Reykjavík, Iceland; 5. Faculty of Food Science and Nutrition, University of Iceland, Reykjavík, Iceland

Kynnir / Presenter: Gregory K. Farrant

Subglacial lakes located beneath the Vatnajökull ice cap are associated with volcanic activity making them good models to study life in extreme environments and potentially similar habitats outside Earth. The core diversity of Skaftárketill was previously shown to comprise bacteria adapted to cold, dark, and nutrient-poor waters. This study presents ongoing research on the ecology of this lake based on two metagenomes sequenced from samples collected at the bottom and along the water column. For each sample, 4.106 single reads were sequenced by Illumina© and analysed. Metagenome-based diversity analyses, using rDNA miTAGs, confirmed the existence of a limited core community among samples with four previously described taxonomic groups together recruiting 95.8% of bacterial rDNA reads and revealed a low abundance of uncharacterised taxa distant to Saccharibacteria (94% id.) and Caldisericum (83% id.). Environmental metagenomes were conservatively assembled into open-reading frames and were functionally and taxonomically identified using KEGG. These analyses reveal extensive genetic novelty with 55.5% of the gene-associated reads not finding any match to a reference sequence with identity equal to or higher than 93%. Functional explorations revealed metabolic pathways for oxidation/reduction of sulfur, nitrogen, carbon fixation via reverse Krebs cycle or acetogenesis, supporting the idea that chemo-litho-autotrophy constitutes the main metabolism in this unique ecosystem.