Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E65
Höfundar / Authors: Solange Duhamel (1), Christopher Hamilton (1), Snæbjörn Pálsson (2), Snædís H. Björnsdóttir (2)
Starfsvettvangur / Affiliations: 1. University of Arizona, 2. University of Iceland
Kynnir / Presenter: Snædís H. Björnsdóttir
The 2014-2015 eruption of Holuhraun in the central highlands of Iceland inundated a segment of the Jökulsá á Fjöllum glacial river, which resulted in an ephemeral hydrothermal system. We investigated the microbial communities and environmental conditions of both the source water and of the water emerging from the lava flow front. The microbial composition differed vastly between the lava-heated water and the glacial river and spring water sources that fed into the system. Several taxonomic and metabolic groups were found confined to the water emerging from the lava and some showed highest sequence similarities to subsurface microbial ecosystems. Different environmental factors had a significant effect on the microbial composition, including temperature, turbidity, dissolved oxygen and pH. Field incubation experiments showed that the temperature difference of glacial water entering and exiting the lava flow-field had a profound effect on the microbial composition. Elevated temperature from about 6 to 18°C increased the cell abundance, diversity and richness. Thermophilic bacteria were isolated from the lava-water environment and the nearby acidic hydrothermal system Víti, and included known endospore-formers. In addition, a strain from a potentially novel taxon was isolated.