What can be found under the ground at a depth of almost 6000 meters below sea level? It would seem that nothing is alive. Researchers from the Woods Hole Oceanographic Institute (USA) also thought so, until they discovered an accumulation of bacteria under the ocean floor. Moreover, only according to preliminary calculations, these are such ancient microorganisms that they over 100 million years! Can these microbes remain alive after such a long time, with little or no nutrition? It turned out, yes, because scientists managed to "revive" these bacteria!
According to scientists, during the expedition theyfound bacteria in soil samples from 5,700 meters below sea level. Moreover, even in such a place, the microorganisms somehow found a small source of oxygen, although the bacteria themselves did not show any signs of life. This suggested that if the microbes were placed in a more nutritious environment, they could start living and multiplying again.
The oldest bacteria in the world
Scientists provided the ground where they foundbacteria, substances for creating a nutrient medium - ammonia, acetic acid salts, as well as isotopes of nitrogen and carbon dioxide. After 557 days, the soil was removed and found approximately thousand bacteria per cubic centimeter... In laboratory conditions, they have already added other nutrients, after which the number of microorganisms was million per cubic centimeter... In 2 months, the bacteria multiplied a thousand times.
This is the first time in history that scientists have been able to revive such ancient microorganisms. In 2019, researchers were able to do a similar thing with bacteria that were about 15 million years.
The discovery proves an "insane" possibility, assaid one of the scientists that microbes are dormant deep underground, or at least grow slowly without dividing for millions of years.
Can bacteria live on other planets?
In addition, the experiment clearlydemonstrated that life is possible even in places that biologists once considered uninhabited. That is, in theory, similar microorganisms can inhabit other places in the solar system or even in the entire universe.
If the surface of a particular planet does not look promising for life there, microorganisms can still dwell deep under it, says Andreas Teske, a microbiologist at University of North Carolina.
Typically one cubic centimeter of marinedirt accounts for at least 100,000 microorganisms. But these samples contained no more than a thousand bacteria in the same amount of soil. That is, despite the fact that bacteria can exist with little or no nutrition, their population is still declining. No one can say that in another 150 million years they will not disappear completely.
If you are interested in science and technology news, subscribe to us on Yandex.Zen so as not to miss new materials!
In the future, biologists plan to develop specialized methods for finding life. in places previously considered uninhabited... In particular, we are talking about usingchemical indicators for detecting the ingress of any bacteria into the soil and seawater, as well as creating a method for analyzing very small amounts of cells and isotopes.
Genetic analysis of microbes showed that theybelong to eight known bacterial groups, many of which are commonly found elsewhere in salt water, where they play an important role in breaking down organic matter.
This suggests that learning to survive in the face of extreme energy constraints is a widespread skill, scientists say.
How long do bacteria live?
Researchers don't know what all these were up tomicrobes for tens of millions of years. Most of the species they discovered showed no signs of life and seemed to "fall asleep", as some bacteria survive in adverse conditions. It is possible that all this time the bacteria were dividing very slowly.
The main thing is that after all these discoveries we do not have any new dangerous bacteria... There are enough of them now.
In 2016, a group of Russian scientists who studiedLake Vostok, which is located in Antarctica, discovered a new type of microorganisms. New types of bacteria are discovered quite often, but in this situation, attention was drawn not by the fact of the discovery itself, but by the fact that microorganisms were only 86% similar to terrestrial ones. The depth, or to be more precise, the thickness of the ice, on which the new life form was discovered, corresponds to layers that are approximately five thousand years old. The bacteria were found to be fully viable and doing well at a temperature of -60 ° C... And in a 2005 study, NASA scientists successfully revived bacteria trapped in a frozen pond in Alaska. for 32,000 years... Microbes called Carnobacteriumpleistocenum have been frozen since the days when woolly mammoths were still roaming the Earth. As soon as the ice melted, they began to swim again as if nothing had happened.
Scientists said that if speculation about extraterrestrialthe origin of the found microorganisms will be confirmed, then this will help to get an idea of what life forms can be developed on other planets.