Swiss scientists have discovered a surprising diversity of bacteria in glacial streams around the world. But upon its discovery, this diversity is already threatened.
For more than five years, a team led by the École Polytechnique Fédérale de Lausanne (EPFL) collected and analyzed samples from 170 glacial streams. The objective of the project, called “Vanishing Glaciers“, is to document these living organisms before they disappear at the same time as the glaciers.
The results of these analyzes were published Wednesday and Thursday in two studies published in the journals Nature and Nature Microbiology. Scientists show that these streams have great microbial diversity.
“Glacial streams are the most extreme freshwater ecosystems on the planet,” said Tom Battin, who led this work at EPFL. We didn’t expect to find much diversity under these conditions, he added.
Temperatures in streams are near freezing and nutrients are scarce. They receive almost no sunlight in winter and are, however, exposed to strong UV radiation in summer, notes the specialist.
Champions of survival
And yet, there is remarkable biodiversity among the microbiome living in these streams. These bacteria are true champions of survival, according to Tom Battin.
To survive in these conditions, they have developed different strategies. Some have formed protective films which protect them from strong UV radiation, others can use different energy sources simultaneously. Additionally, the bacterial microbiome of glacial streams is unique. It is clearly distinguished from that of glaciers.
According to the researcher, it is also striking that many bacteria only appear in a given mountain range. In New Zealand and Ecuador in particular, scientists have found many bacteria that do not exist anywhere else.
A race against time
Studying the microbiome of glacial streams is a race against time. With the retreat of glaciers, it is strongly threatened, underlines Professor Battin. “But it is a biodiversity that we do not see, but without which the biodiversity that we see, that is to say that of plants and animals, would not exist,” he says.
According to the researcher, the genetic repertoire of these bacteria is also of great importance. For example, scientists are looking for enzymes that are active at very low temperatures, which could therefore be useful in industrial processes, for example in laundry cleaning or papermaking.
These microorganisms could also contribute to the development of new antibiotics and play a key role in the fight against antibiotic resistance. “We need to explore this genetic toolbox before glacial streams disappear,” concludes Tom Battin.
ats/lan
