When you’re trying to survive in the icy wastes of Antarctica, you need all the help you can get, and it turns out that some marine worms survive by forming relationships with bacteria that produce something like natural antifreeze. These bacteria live on the worms and secrete proteins that protect them from the icy water in return for their hospitality.

According to the research team, made up of researchers from several institutions in Italy, this is an important step forward in our understanding of the relationships between microbes and the organisms with which they have a mutually beneficial relationship.

“Multicellular organisms in the oceans live in close association with their microbiomes, which provide their hosts with essential functions including nutrient supply, defense mechanisms, and even additional metabolic pathways,” the researchers wrote in their published paper.

The team visited several coastal areas of Antarctica to collect sediment samples and found three worms: a polychaete (Leitoscoloplos geminus, Aphelochaeta palmeri And Aglaophamus trissophyllusThe average water temperature was 1°C below zero, too cold for these worms to survive on their own.

Enter bacteria Meiothermus And Anoxibacillarywork to combat frostbite caused by internal worms. Specifically, proteins in these bacteria produce the chemicals proline and glycol, which lower the freezing point of their internal fluids and prevent ice from forming in their cells, much like antifreeze does in liquids.

Other creatures in such extreme conditions can also produce similar antifreeze proteins themselves; icefish are one example. These worms need some symbiotic help from local bacteria, the researchers say: “These findings suggest that the bacterial core of Antarctic polychaetes is driven by biological interactions between hosts and associated bacteria.”

The researchers believe this connection has existed for a very long time, as generations of these marine worms passed down bacteria from generation to generation, perhaps helping these species establish themselves in Antarctica, but more research is needed to confirm this.

As for how this new knowledge can be applied, one area where it could be used is in cryopreservation: keeping cells alive but at low temperatures. Of course, this also gives us new insight into the delicate balance of marine life in Antarctica, a balance that continues to be threatened by rising temperatures.

We know that living in such conditions means different types of adaptations to make the most of available resources and to cope with conditions that would make life in the icy wastes impossible.

“The results of this study open broader perspectives for understanding the adaptation and freezing resistance mechanisms of marine invertebrates by related bacteria,” the researchers write. The study was published in: Science Developments.