New ‘fire amoeba’ breaks heat survival record

{"text":[[{"start":7.04,"text":"A shape-shifting organism discovered in scalding hot springs has broken the temperature record for complex life forms to thrive, marking a milestone in efforts to understand how creatures withstand extreme heat."}],[{"start":19.92,"text":"Scientists found that the protein-armoured “fire amoeba” from California’s Lassen Volcanic National Park flourished at 63C, propelling it into the exclusive club of “extremophile” organisms existing in Earth’s most severe environments."}],[{"start":35.52,"text":"Extremophiles found in places from the poles to the ocean floor offer evolutionary insights and potential practical applications, from laundry detergents to food preservation."}],[{"start":44.68,"text":"“This finding pushes the bounds of what we thought was possible, which is incredibly exciting,” said Angela Oliverio, a researcher from Syracuse University in New York."}],[{"start":55.1,"text":"She said there could be more complex organisms with distinct internal cell structures — known as eukaryotes — “that can survive at even higher temperatures than we know of”."}],[{"start":null,"text":"

"}],[{"start":65.2,"text":"Oliverio and colleagues named the previously unknown organism Incendiamoeba cascadensis, roughly “fire amoeba from the Cascades”, in reference to its hardiness and the mountainous region where it was collected."}],[{"start":78.32,"text":"In laboratory tests reported on Tuesday in the journal Cell, they found that it grew well at 57C — the previous amoeba world record — and was still duplicating itself at 63C. It was able to survive exposure to 70C temperatures by changing its shape and forming a protective outer layer, then recovering once its environment cooled down."}],[{"start":102.64,"text":"Tests revealed that the organism had extra genes associated with protein maintenance and DNA repair, compared with amoebas living in less hot conditions, the researchers said."}],[{"start":112.84,"text":"The fire amoeba’s proteins seemed to share stabilising structural adaptations shown by simpler non-eukaryotic organisms that are capable of withstanding high-temperature environments. The extreme heat champion is the Methanopyrus kandleri, which lives around deep ocean hydrothermal vents and can survive at temperatures of up to 122C."}],[{"start":134.06,"text":"Other extremophiles include tardigrades, microscopic creatures nicknamed water bears that can survive stresses including extreme temperatures, oxygen deprivation and radiation by entering a dormant state."}],[{"start":146.68,"text":"Larger animals that show unique adaptations include the Antarctic icefish, the only known vertebrate without haemoglobin — the oxygen-carrying substance that makes blood red."}],[{"start":157.04,"text":"Substances derived from simple organisms that live at elevated temperatures already have industrial uses. Specialised proteins known as enzymes discovered in Thermus aquaticus, a geothermal bacterium found in Yellowstone National Park, are used in genetic testing and medical diagnostics."}],[{"start":174.4,"text":"The fire amoeba and other complex organisms living in extreme environments might “represent a new reservoir of potentially useful biotechnological compounds”, said Lee Hutt, lecturer in biomedical sciences at the University of Plymouth. They could open the way to new methods of engineering cells or crops that have greater tolerance to high temperatures, he added."}],[{"start":194.36,"text":"The fire amoeba is a “reminder of both the resilience of life and the limits of our understanding of where life can exist”, Hutt said."}],[{"start":202.24,"text":"The discovery of a complex organism that can endure high temperatures has an emotional resonance at a time of planetary warming, Hutt and other researchers said."}],[{"start":210.72,"text":"The fire amoeba’s adaptability is in some ways “reassuring” but even it is not safe from environmental change, noted H Beryl Rappaport, another of the organism’s researchers. Global heating could dry up its geothermal streams and kill the plants on which its ecosystem relies for nutrients."}],[{"start":227.64,"text":"“Finding extremophiles feels hopeful and inspiring — but does not make concerns any less pressing,” Rappaport said."}],[{"start":234.92,"text":""}]],"url":"https://audio.ftcn.net.cn/album/a_1790254210_4053.mp3"}