The same bacteria live in the Arctic and Antarctic

Microbial WGs at the poles are surprisingly similar

On the trail of teeming life: Geoscientist Julia Kleinteich takes freshwater samples in the Antarctic. © Daniel Farinotti
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Tiny globetrotters: Although Arctic and Antarctic are located on opposite poles of the earth, apparently similar bacteria feel comfortable there. A study shows that the microbial WGs in these two remote regions are surprisingly similar. How exactly the bacteria from the north to the south and thereby overcome barriers such as oceans, is still unclear. It is conceivable that it could spread through the atmosphere or through birds and humans, the researchers write.

Whether on our bodies, in rivers and lakes or on a tiny grain of sand - you can only see it closely, it's teeming with everything: bacteria. The little microbes have conquered even the last corners of the earth for themselves. Even in regions as remote as the polar regions, they come to host. But which species are there exactly?

Researchers have posed this question to Julia Kleinteich of the University of Tübingen and now compared the teeming life in the Arctic and Antarctic now for the first time. For their study, they sequenced DNA from freshwater bacteria and biofilms of the terrestrial regions at the poles. The samples originated among others from the British research station Rothera on the Antarctic Peninsula and the Norwegian archipelago Spitzbergen in the Arctic.

Successful generalists

The comparisons revealed something astounding: "Despite the large geographic distance, bacterial diversity includes some of the same species, " the scientists report. "So some microorganisms have the potential to spread globally across barriers like oceans."

The mechanisms for this are still unclear: it is conceivable that it could spread through the atmosphere or through birds and humans. Since comparative samples of temperate latitudes have also been found to overlap the polar microorganisms, the bacteria are likely to be generalists, as Kleinteich and her colleagues suspect - microorganisms that could survive in a wide range of environmental conditions. display

Similar response to climate change

But not all Polbewohner occur in the north and the south: The researchers also came to bacteria that occurred exclusively in the region. "The proportion was larger in the more isolated Antarctic, which seems to have a partially unique diversity of microorganisms and is therefore particularly worthy of use, " says Kleinteich.

The study of the distribution patterns of species, the so-called biogeography, provides insights into how ecosystems respond to environmental changes such as climate change. According to the latest results, it can be expected that both Arctic and Antarctic microorganisms responded to climate change in the same way, the scientists write.

Last return room

"This already shows strong effects at the poles due to an increase in temperature, in some cases to over 0 degrees Celsius and a glacier and snow melt, " says Kleinteich. However, while the Antarctic still offers a retreat for microorganisms, the alternative options in the Arctic are almost exhausted even for species-adapted mammals.

In further studies, the team is currently exploring glacier regions in the Swiss Alps that have similar climatic conditions as the polar regions. "We investigate whether alpine regions serve as islands in the distribution of culturally adapted organisms, and whether climate change is changing bacterial diversity and thus their ecosystem, " they conclude. (Frontiers in Ecology and Evolution, 2017; doi: 10.3389 / fevo.2017.00137)

(Eberhard Karls University T bingen, 14.12.2017 - DAL)