Bacterial community structure in a sympagic habitat expanding with global warming: brackish ice brine at 85–90 °N

• Published in: The ISME Journal
• Main Authors: Fernández-Gómez, Beatriz, Díez, Beatriz, Polz, Martin F., Arroyo, José Ignacio, Alfaro, Fernando D., Marchandon, Germán, Sanhueza, Cynthia, Farías, Laura, Trefault, Nicole, Marquet, Pablo A., Molina-Montenegro, Marco A., Sylvander, Peter, Snoeijs-Leijonmalm, Pauline
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2019
• Subjects: Microbiology; Ecology; Evolution; Behavior and Systematics; Antarctic; Arctic; Arctic Ocean; Antarc*; Global warming; Sea ice
• Online Access: https://doi.org/10.1038/s41396-018-0268-9; https://repositorio.uchile.cl/handle/2250/171328

© 2018, International Society for Microbial Ecology.Larger volumes of sea ice have been thawing in the Central Arctic Ocean (CAO) during the last decades than during the past 800,000 years. Brackish brine (fed by meltwater inside the ice) is an expanding sympagic habitat in summer all over the CAO. We report for the first time the structure of bacterial communities in this brine. They are composed of psychrophilic extremophiles, many of them related to phylotypes known from Arctic and Antarctic regions. Community structure displayed strong habitat segregation between brackish ice brine (IB; salinity 2.4–9.6) and immediate sub-ice seawater (SW; salinity 33.3–34.9), expressed at all taxonomic levels (class to genus), by dominant phylotypes as well as by the rare biosphere, and with specialists dominating IB and generalists SW. The dominant phylotypes in IB were related to Candidatus Aquiluna and Flavobacterium, those in SW to Balneatrix and ZD0405, and those shared between the habitats t