By Riddhi Kannabiran
Scientists have long thought that there were limits to how much heat complex living cells could withstand. A newly discovered microorganism, however, is capable of reproducing temperatures as high as 63 degrees Celsius, or 145 degrees Fahrenheit, giving it the nickname “fire amoeba”. The fire amoeba’s remarkable ability to survive extreme heat is giving scientists a new understanding of where, and how complex life exists.
This discovery was made in a geothermal environment in Lassen Volcanic National Park In Northern California. Researchers collected samples from hot springs and brought them back to laboratories for further investigation. Within the samples the researchers identified an unfamiliar amoeba that continued living in temperatures that would normally be considered too extreme for a complex cell. The species is named Incendiamoebaa casadensis, meaning approximately ‘fire amoeba from the cascades” referencing where they were discovered.
What makes this discovery especially interesting is the organism’s ability to reproduce within extreme heat, this has never been seen before in eukaryotes, or multicellular organisms. Eukaryotic cells are generally considered more vulnerable to extreme heat than simpler cells such as bacteria and archaea. Scientists had previously regarded approximately 60 degrees Celsius as an important upper boundary for eukaryotic cells; this boundary is now being reconsidered with the discovery of the amoeba.
Researchers are now investigating how the organism manages to survive conditions that damage ordinary cells. Extreme heat can cause proteins to lose their structures, disrupt cell membranes, and damage genetic material. Genetic analysis of the I casadensis revealed some adaptations involving protein stability, genome protection and responses to environmental stress. Understanding these adaptations and how they were made could aid scientists in learning more about how living cells can protect themselves under extreme conditions.
The Amoeba’s environment explains why it has developed such unusual characteristics, the amoeba lives in hot springs where the organism feeds on heat adapted bacteria. The extreme environment may reduce competition from organisms that cannot survive the high temperatures, allowing the amoeba to occupy a specialized niche. Scientists had also forum related genetic sequences in geothermal environments outside California, including locations in New Zealand and Yellowstone which suggest that there are other organisms that remain undiscovered that can thrive in extreme heat.
This discovery could have implications beyond understanding life on Earth. Scientists searching for life elsewhere in the solar system often consider temperature when determining whether an environment could support organisms. Finding a complex organism capable of surviving temperatures once thought impossible expands scientists’ ideas about where life could be found, and where life could survive. The continued research of organisms’ ability to survive in extreme conditions could lead more advancements towards figuring out how advanced life can live in extreme environments, as humans venture further into space parts of our own earth. Research like this could be revolutionary in supporting human explorations