New organism discovered that thrives at 63°C

Scientists have discovered a new species of organism that can thrive at 63°C, challenging long-standing understandings of the heat tolerance limits of eukaryotes and opening up new avenues of research.

Microscopic image of single-celled amoeba-like cells - Photo: sciencealert.com

According to Nature , scientists have just found a single-celled amoeba that can thrive at temperatures of 63°C - a temperature that can destroy all other known complex life forms (organisms with cells containing nuclei and intracellular structures).

The discovery challenges the long-held notion that eukaryotes – the group that includes both animals and plants – are not suited to the harsh conditions typically inhabited by bacteria and other organisms without a cell nucleus.

"We need to seriously rethink the limits of what a eukaryotic cell can do," says Angela Oliverio, a microbiologist at Syracuse University in New York.

Ms. Oliverio and her colleague Beryl Rappaport discovered this creature in Lassen Volcanic National Park (California, USA). They named it Incendiamoeba cascadensis, which roughly translates to "fire amoeba from the Cascades".

Although Lassen Park is famous for its boiling acid lakes and fiery geothermal pools, I. cascadensis was found in a pH-neutral hot spring and appeared quite ordinary.

Initially, water samples from the stream appeared completely sterile under a microscope. However, after culturing them with nutrients, the researchers discovered the amoeba was growing at 57°C.

As the scientists gradually increased the experimental temperature, the organism easily surpassed the previous eukaryotic heat resistance record of 60°C (which belonged to some fungi and red algae). The results showed that I. cascadensis could still divide cells at 63°C and move at 64°C. Even at 70°C, these cells could form dormant "cysts" that could reactivate when the temperature dropped.

By comparison, the most resilient bacteria and archaea can withstand much higher temperatures, with the current record holder being Methanopyrus kandleri at 122°C. However, for complex cells like those of mammals and humans, the limit is typically around 43°C. So the fire amoeba's tolerance is a remarkable leap forward for eukaryotes.

Julia Van Etten, an evolutionary biologist at the University of Maryland, said the discovery underscores the importance of scouring the planet for new creatures. "The team has found a species that does something we thought was impossible for eukaryotes," she said. "So what else is lurking out there?"

According to author Oliverio, scientists have previously paid little attention to eukaryotes that endure extreme conditions. Studying them could bring new insights into biotechnology as well as the search for life beyond Earth.

“We only found one stream. Maybe we were extremely lucky, or maybe they are more common than we think,” she said.

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Source: https://tuoitre.vn/phat-hien-sinh-vat-moi-sinh-soi-o-nhiet-do-63c-20251203092840817.htm