Laval University scientists identify a new class of bacteria that plays a key role in one of Canada’s most northerly lakes
Lake A, located on Ellesmere Island in Canada’s High Arctic, has been isolated from the world for millennia. "It’s a kind of lost world, untouched by human disturbance. The environmental conditions are particularly favourable for the study of microorganisms and their potential," stresses Adrien Vigneron, former postdoctoral fellow in Warwick Vincent’s North Sentinel team, and Connie Lovejoy, from the Faculty of Science and Engineering.
The team discovered the new family of microbes following genomic sequencing of the lake. The scientists realized that a quarter of the microbiome in the deepest waters was made up of unknown microorganisms. "Their genomic sequences had almost no correspondence with current databases, which allowed us to conclude that a new microbial species is colonizing the deep, salty, sulfuric waters of the lake," explains the former postdoctoral researcher.
Further genome analysis has revealed more about its peculiarities and capabilities. These new microorganisms appear to be a major contributor to the sulfur cycle in the waters of Lake A, a relic of the Arctic Ocean. To compete with surrounding bacteria, these microbes produce an antibacterial. "Our results indicate that these bacteria can out-compete other microorganisms by relying on a combination of metabolic versatility and biotoxicity", reports Adrien Vigneron.
Unprecedented biodiversity
This discovery shows that there are still microbial groups that have never been observed, and whose novel functions could be of interest for applied research. "It confirms that Arctic ecosystems host a unique biodiversity that must be preserved," he adds.
After several exchanges with the inhabitants of the northern villages near Lake A, the team named this microbial species "Tariuqbacteria", based on "tariuq", which in Inuktitut means "salt water or ocean". "It was a way of highlighting the richness of the North and preserving the origin of this novel microbial species," reports Adrien Vigneron.
From the point of view of basic research, this discovery has also enabled us to uncover new evolutionary strategies and original metabolic pathways to explain the ecological success of this species in the deep waters of the lake.
The study, entitled "Discovery of a novel bacterial class with the capacity to drive sulfur cycling and microbiome structure in a paleo-ocean analog", was published in the scientific journal ISME Communications.
