May 3, 2024

Surviving the Extremes: Exploring the Existence of Life at 125°

Oliverio and Rappaport carried out field research over the summer at Lassen Volcanic National Park in California, which contains lots of hydrothermal features. Credit: Syracuse University
Biologists from Syracuse University are taking a look at the procedures that allow microbial eukaryotes to thrive in the extreme environment of a geothermal lake.
It is estimated that the Earth is home to around 8.7 million species of eukaryotic organisms. Eukaryotes are identified by the existence of a nucleus and other membrane-bound organelles within their cells. Despite the typical association of eukaryotes with animals and plants, these types in fact comprise simply two of the over six significant eukaryotic groups.
A substantial part of eukaryotic variety is comprised of single-celled microorganisms known as protists. Researching these organisms allows researchers to explore the evolutionary paths that have actually contributed to the rich variety and complexity of eukaryotic life. Such investigations provide understanding of the advancements, such as the development of multicellularity, which enabled the existence of animal life in the world.
As researchers pursue a much better understanding of the mechanisms behind the advancement of species in the world, questions remain about how microbial eukaryotes adapted to the worlds severe environments. To dive further into this topic, researchers in the College of Arts and Sciences (A&S) Department of Biology are presently examining protists that populate some of the harshest environments on Earth: acidic and extremely hot geothermal lakes.

These were sampled from a geothermal lake at Lassen Volcanic National Park. Figuring out how this types adjusted to this severe environment could expand the understanding of what types of environments in the Universe may be considered appropriate for life.
This previous summertime, Oliverio and Rappaport took a trip to Lassen National Park to find out more about this particular protist and to browse for other unique extremophilic eukaryotes. Later, the bottles were carried back to Oliverios lab at Syracuse and the team is currently separating single cells for genome sequencing and identifying the amoebae by microscopy.
Syracuse University researcher Hannah Rappaport dipping a bottle into a hot lake to obtain a sample.

A&S biologists Angela Oliverio, left, and Hannah Rappaport at the United States largest geothermal lake at Lassen Volcanic National Park in California. Credit: Syracuse University
A group led by Angela Oliverio, assistant professor of biology, just recently returned from Lassen Volcanic National Park in California, home to the largest geothermal lake in the U.S.
” This lake is an acid-sulfate steam-heated geothermal feature, indicating it is both rather hot (~ 52 ° C/124 ° F) and acidic (pH ~ 2),” states Oliverio, who began at Syracuse University in 2022. “This makes it a really distinct environment to study polyextremophiles, which are organisms that have adjusted to 2 or more extreme conditions– in this case, heat and low pH.”
So how did they know to travel to a hot lake in California to discover microbial eukaryotic life? In a recent study published in Nature Communications co-authored by Oliverio and Hannah Rappaport, a researcher in Oliverios laboratory, the team developed a database of previous research studies that looked for microbial eukaryotic life across severe environments. Specifically, they analyzed which eukaryotic lineages were spotted several times from various research studies under comparable ecological conditions.
Image of amoebae (circular gray areas in the background) and red algae (four white ovals in the foreground), photographed by Hannah Rappaport using light microscopy. These were sampled from a geothermal lake at Lassen Volcanic National Park. Credit: Syracuse University
” We discovered that several lineages of amoebae were often recuperated from incredibly high-temperature environments,” states Oliverio. “This recommends that studying those family trees may yield terrific insight into how eukaryotic cells can adjust to life in very hot environments.”
According to Oliverio, one specific study carried out by Gordon Wolfes laboratory at Cal State Chico revealed an amoeba, T. thermoacidophilus, was rather plentiful in Lassen National Parks geothermal lake. No genomic information on this organism exists. Figuring out how this types adapted to this severe environment might expand the understanding of what kinds of environments in deep space might be thought about suitable for life.
This previous summer season, Oliverio and Rappaport took a trip to Lassen National Park to discover more about this particular protist and to look for other novel extremophilic eukaryotes. At the lake, the team used a long painters pole affixed with a 1-liter bottle to acquire samples– no easy task considering the water is well over 100 degrees Fahrenheit. Afterward, the bottles were transferred back to Oliverios laboratory at Syracuse and the group is currently isolating single cells for genome sequencing and defining the amoebae by microscopy.
Syracuse University researcher Hannah Rappaport dipping a bottle into a hot lake to get a sample. Due to the high temperature of the water and unstable ground, scientists should remain at a safe range away when collecting samples. Credit: Syracuse University
While many unknowns remain about how eukaryotes adapt to exist in extreme environments, Oliverio is enthusiastic that this research study will assist close a few of the present knowledge gaps.
Image of amoebae (circular gray spots in the background) and red algae (4 white ovals in the foreground), photographed by Hannah Rappaport utilizing light microscopy. These were tested from a geothermal lake at Lassen Volcanic National Park.
” We believe that there is something unique about the amoeboid form that allows persistence in these eukaryotic family trees, however the mechanism stays unknown,” she says. “Based on our research study, we assume that horizontal gene transfer (movement of hereditary details between organisms) from bacteria and genome reduction (when a genome erases genes it does not require), in addition to the growth of especially useful gene families, might be a few of the methods which protists have gotten the toolkit to endure in extreme environments.”
Oliverio notes that the groups genome-scale findings will contribute crucial missing out on information into reconstructions of the tree of life. “This will even more our understanding of the circulation and evolution of life on Earth.”
Reference: “Extreme environments offer an extraordinary chance to comprehend microbial eukaryotic ecology, advancement, and genome biology” by Hannah B. Rappaport and Angela M. Oliverio, 16 August 2023, Nature Communications.DOI: 10.1038/ s41467-023-40657-4.