While I was researching boring organisms that drill holes in rocks, I came across a story about microorganisms that live in the harsh environment of underground rocks. They’re called extremophiles. There are microorganisms that live in environments where normal organisms could never survive. Apparently, microorganisms that have lived for about 100 million years have been found in a stratum 5,000 meters deep where there is almost no nutrition and even microorganisms cannot move. Even if there is no concept of a lifespan for microorganisms, 100 million years is an amazing time.
https://gendai.media/articles/-/101341
Other extremophiles include psychrophilic microorganisms that can live in temperatures close to freezing, thermophilic microorganisms that can live in temperatures close to 100°C, acidophilic microorganisms that can live in strong acids, alkaliphilic microorganisms that can live in strong alkalis, halophilic microorganisms that can live in high salt concentrations, barophilic microorganisms that can live under high water pressure, and radiation-resistant microorganisms that can live under strong radiation. I think I understand now why microorganisms have been discovered all over the Earth. And why there are said to be so many unknown microorganisms.
https://micsmagazine.com/basic/2297/post
There are also microorganisms called organic solvent-resistant microorganisms that can grow in organic solvents such as toluene. Organic solvents are liquid organic compounds that have the ability to dissolve other substances, and representative examples include alcohol, ethanol, and acetone. It seems unlikely that any living organisms could survive in them, but microorganisms are amazing.
https://kato-lab.hiroshima-u.ac.jp/
This also seems to be an extreme environment, but there are microorganisms in the stratosphere. The stratosphere is an area with an ozone layer at an altitude of 10 to 50 km. Ozone is thought to be toxic to living things, and the air pressure is thought to be extremely low. They are also called airborne organisms or aeroplankton. There is also thought to be little oxygen, so they may also be anaerobic microorganisms that can live in the absence of oxygen.
https://www.perc.it-chiba.ac.jp/projects/biopause
I researched microorganisms that live in harsh environments, and I was impressed by their incredible vitality and ability to acquire resistance. I think there must be some meaning to living in such an environment, but I hope that one day we will understand whether it is for the purpose of decomposition and circulation, or some kind of communication through living organisms. Thanks to microorganisms, I feel like the outlines of the existence of each substance and living organism become unclear. Microorganisms are amazing, and the Earth is amazing.
