What's Lurking Under the Antarctic Ice Sheets?

Bacteria are a very diverse group of organisms. They can utilize many different metabolic pathways to consume and/or make food in their own special way. We characterize these bacteria into different groups based on how they consume or make food, and call different groups heterotrophs, autotrophs, etc.

Categories of bacteria based on nutrition intake and metabolic methods

But what if I told you that some bacteria can choose how they want to consume their energy? These bacteria are none other than the ones found under the Antarctic ice sheets. These tiny organisms are able to shift their trophic ability based on their environments.

This means that they can change what kinds of food they ingest and how they use that food based on what's available to them. The team of researchers that uncovered this information found that the bacteria can change between eating organic carbon sources like dead cells and absorbing carbon dioxide to make their own food like plants do. The researchers claim that this versatility allows them to survive and is the reason they have actually survived for so long.

The water that flows through rivers and into the subglacial lakes often varies in the levels of oxygen it carries in, so the change in metabolic pathways discussed above is crucial for the survival of these bacteria. Additionally, instead of using sunlight to be the energy source behind their absorption of CO2, the bacteria are able to use other metabolic pathways that allow them to gain that energy from iron or sulfur that's found in the crushed rocks and minerals in their habitats.

This discovery, of these bacteria that act like Swiss Army knives in the way they can change up how they use and process nutrients available to them, an incredible one! This information can change the way we think about and classify bacteria, and it could be a glance into the future of the bacteria we find around us now. If ancient bacteria can adapt and find new ways to survive, can't modern ones do the same?

Reference article: Fox, D. (2025, September 3). Antarctic lake microbes have flexible survival strategies. Science News. https://www.sciencenews.org/article/antarctic-microbes-survival-strategies