Hot springs in Lassen Volcanic National Park, where heat-tolerant amoeba were discovered.Credit: Kelly Vandelen/iStock via Getty
This hive likes it hot. Tiny, single-celled amoeba can thrive at temperatures that would kill all other known complex life forms, organisms whose cells contain a nucleus and internal skeletons.
The discovery calls into question the idea that such “eukaryotic” life – which includes all animals and plants – is not suited to the kind of extreme conditions endured by bacteria and other organisms that lack a cell nucleus.
“We need to rethink what is possible for the eukaryotic cell in an important way,” says study co-author Angela Oliverio, a microbiologist at Syracuse University in New York. The work, which has not yet been peer-reviewed, was described in a preprint dated 24 November1.
Oliverio and fellow Syracuse microbiologist Beryl Rappaport discovered the organism in Lassen Volcanic National Park in Northern California’s Cascades Mountain Range. They called it Encindamiba Fallswhich translates to “fiery amoeba of waterfalls” in Latin.
Encindamiba Falls It can thrive at temperatures that would kill other complex cells.Credit: Image by Natalie Petek Siwan from the preprint by H. Beryl Rappaport et al./bioRxiv
The park is famous for its flowing acid lakes and colorful glowing geothermal pools, but… I. cascade It comes from a pH neutral “hot stream”. “It’s the most interesting geothermal feature you’ll find in Lassen,” Rappaport says.
Water samples from the river appeared devoid of life under a microscope, but after culturing the samples with nutrients, the researchers observed the amoeba growing at 57 degrees Celsius, within the river’s temperature range. They slowly raised the temperature, surpassing the previous eukaryotic record of 60 degrees Celsius. I. cascade It was still split at 63°C, and at 64°C, it was still moving. Even at 70°C, cells can form dormant “cysts” capable of being reactivated at cooler temperatures.