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Researchers are taking samples of sediment nuclei from the sea depths.
Microbes buried under the seabed for more than a hundred million years are still alive, a new examination reveals. Once taken to the lab and fed, they began to multiply. Microbes are oxygen-loving species that exist in the low fuel that is released from the surface of the ocean to the seabed.
The discovery raises the “meaningless” possibility, as one scientist put it, that microbes in inactive sediments, or at least grow slowly without dividing, during eons.
The new paintings show that “microbial life is very persistent and discovers a way to survive,” says Virginia Edgcomb, a microbial ecologist at the Woods Hole Oceanographic Institution who was not interested in paintings.
Moreover, it seems that life can enter places that biologists once thought were uninhabitable, studies suggest the option of living elsewhere in the solar system or elsewhere in the universe. ”If the surface of a specific planet doesn’t look promising for life, it can have compatibility in the basement,’ says Andreas Teske, Chapel Hill microbiologist at the University of North Carolina, who also did not participate in the new study. . Training
Researchers know that life has existed “under the ground” of the ocean for more than 15 years. But geomicrobiologist Yuki Morono of the Japanese Marine Earth Science and Technology Agency sought to know the limits of that life. Microbes are known to live in very hot or poisonous environments, but can they live where there is little food to eat?
To locate him, Morono and his colleagues organized a drilling expedition on the South Pacific turn, an existing site across the ocean in eastern Australia that is considered the most lethal component of the world’s oceans, almost without the nutrients needed for survival. When they extracted clay nuclei and other sediments up to 5700 meters below sea level, they showed that the samples involved oxygen, a sign that there is very little biological matter to eat through bacteria.
Bacteria extracted from hundred million-year-old clay
To explore what life might be like there, Morono’s team carefully extracted small clay samples from the center of the perforated nuclei, put them in glass vials, and added undeniable compounds, such as acetate and ammonium, containing a heavier bureaucracy (or isotopes) of nitrogen. . and the carbon that can be detected in living microbes. The day the organization first “fed” the dust samples with these compounds, and up to 557 days later, the team extracted pieces of clay from the samples and dissolved them to detect live microbes, despite the lack of food for them in clay.
The paintings were hard. As a general rule, there are at least 100,000 cells with a cubic centimeter of dust on the seabed. But in those samples, there were no more than 1000 bacteria in the same amount of sediment. For example, biologists had to expand specialized techniques such as the use of chemical tracers to trip over polluting seawater entering samples and expand a way to analyze very small amounts of cells and isotopes. “The preparation and care needed to make these paintings was indeed impressive,” says Kenneth Nealson, a retired environmental microbiologist at the University of Southern California.
The added nutrients awakened the oxygen of a variety of bacteria. In samples of the 101.5 million-year-old layer, microbes rose from 4 orders of magnitude to more than one million cells consistent with cubic centimeter after 65 days, the team reported today at Nature Communications.
Others discovered bacteria in oxygenated sediments under the seabed. Last year, William Orsi, a geobiologist at Ludwig Maximilian University in Munich, described living sediment bacteria of 15 million years, a past record. “But this examination pushes it back in an order of magnitude in terms of geological time,” Orsi says.
Genetic research of microbes revealed that they belonged to more than 8 known bacterial groups, many of which are commonly found in other parts of salt water, where they play a vital role in the breakdown of biological matter. “This suggests that learning to withstand excessive energy limitation situations is a widespread skill,” says Nealson, a skill that would possibly have evolved early, when there wasn’t much that microbes could also feed on. “It would probably have been a very practical survival trick.”
Researchers don’t know what rotating microbes have done for those millions of years. Most of the species they discovered do not shape spores, which are an inactive standard of living that some bacteria shape under adverse conditions. Bacteria would likely divide very slowly throughout this time, which would cause other remote people in this study to examine the remote descendants of ancestors of millions of years.
But there’s so little food in the sediments on the seabed that the microbes discovered there are likely to do little more than fix the broken molecules. “If they don’t divide at all, they live a hundred million years, but it sounds crazy,” says Steve D’Hondt, university of Rhode Island oceanographer, Bay Campus, and co-author of the studio. He wonders if there is any other unrecognized energy source, radioactivity, that allows a slow department through the bacteria, which were likely trapped in those sediments while buried through other sediments.
But the bottom line, says Bo Barker Jurgensen, a marine microbiologist at Aarhus University who is not interested in work, is that “the small amount of food and energy does not seem to set the maximum limit of life on Earth.”
Liz is a senior correspondent who covers many facets of biology for science.
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