Germs Could Save Us: Little Wizards in Danger

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Are you on solid ground? So not figuratively, but physically, with your body? Yes? Actually you are wrong. The floors of our buildings are littered with microscopically tiny cavities, cracks, grooves and fissures, as well as soil and rocks ripped through to the deepest layers. But these spaces are not empty, they are filled with an enormous amount of life. And this life, at least in the upper layers of the earth, is in danger according to the latest data. They are microbes, or rather nitric bacteria, that process dead organic matter in such a way that plants can reabsorb them as mineral nutrients.

Extensive agriculture, monocultures, climate change and air pollution have greatly increased the diversity of microbes in recent months, as several research and articles in specialist journals such as Science have demonstrated. The various microbes essential to life on our planet are still relatively unknown and hardly ever studied. Take, for example, a branch of research that has only existed for about 20 years, that literally digs deep and basically asks deep questions about life.

Billions of unknown creatures under our feet

Welcome to the fascinating kingdom of microbes of the deep earth’s crust. Deep means thousands of meters: In 2018, researchers found living microbes five kilometers below sea level during deep-sea drilling – by comparison: Mount Everest, the summit of the world’s tallest mountain, is about 8.8 kilometers above sea level. By drilling at more than 40 locations around the world, the researchers estimate that the biomass of these microbes is 200 times the biomass of all humans living on the planet today.

Assuming that the weight of a microgram is approximately one millionth of a microgram, or a mathematically written picogram (10^-12 gram) becomes clear: There is a genetic noise under our feet, which supposedly stand on such solid ground: Billions of billions of bacteria. To be more precise, 40 billion tons of microbes – the largest biome or ecosystem on Earth. And it’s extremely diverse, as the gene sequencing shows: Microbes found thousands of meters below the earth’s surface or seafloor, thanks to deep-sea drilling, are genetically very different. To make a comparison: Humans are genetically more closely related to pine trees than microbes are related to each other.

Are you doing almost nothing – and still fascinating

A sloth is almost hyperactive compared to the activity level of a microbe deep in the earth’s crust: Researchers such as ocean microbiologist Karen Lloyd of the University of Tennessee, USA, hypothesize that the various microbes found did not perform a single cell division in about a year. 5000 years And not much has happened in Petri dishes where researchers have been trying to breed the microbes obtained since the first sounding in 2002: the microbes are floating around a bit, so to speak. There is currently no theoretical limit limiting the lifespan of a single-celled organism. Lloyd sees enormous potential in the slowness of these microbes, though speculative: for example, if processes that contribute to slow metabolism could be applied to cancer cells.

Therefore, to make statements about them, it is necessary to resort to comparisons and investigate how “fast” microbes on the surface behave. If you put Escherichia coli, a gut bacterium we all carry, in a Petri dish and starve it for months or years without food, most of the culture will die. The small surviving fraction is stronger and tougher compared to the “fresh” coli bacteria. Lloyd says this oft-repeated initiative is proof that “there is an evolutionary advantage to being extraordinarily slow.” It also means that microbes in the deep layers of the earth are incredibly resilient. They’re almost unbreakable – after all, they’ve been living on very little energy for thousands of years.

To be precise, these microbes live on only one ceptowatt a day, as US geobiologist and geochemist Doug LaRowe of the University of Southern California has calculated. One ceptowatt (10^-21W) The energy is incredibly small, approximately enough to be hypothetically produced when the mass of a grain of salt is reduced by one nanometer – the thickness of the writing paper divided by a hundred thousand – once a day. This finding is a scientific breakthrough in itself: It was previously assumed that much more energy was needed to make life possible. However, it is extremely interesting how such microbes not only live, but also how they live: With neither sunlight, oxygen, and very few nutrients, they depend on chemical processes that occur due to elements found in the deep layers of the earth. soil is present, including iron, phosphorus, or nitrogen.

Chemical metabolism without oxygen and sunlight

One of these microbes has a special role: Similar to plants, which convert sunlight into biomass through photosynthesis, thereby producing oxygen and nutrients for entire food chains as waste products, chemolithoautotrophs are a link in the existence of most living things. underground biome. Microbes use chemicals (“chemo”) from rocks (“litho”) to produce their own food (“autotrophic”). Chemolithoautotrophs do this with a wide variety of chemicals – sulfur, manganese, iron, nitrogen. Some can even make their food from pure electrons. Again, if you have an unsafe power cord, these germs can directly absorb that power and turn it into other products. The waste products of these and other microbes are minerals such as pyrite or limestone. Minerals that in turn provide the nutritional basis for countless other microbes and also make our world geologically richer.

Such soil microbes not only helped create our world, as they have for millions of years, but pointed far beyond the earth’s crust into space. When microorganisms can survive for thousands of years without sunlight and oxygen and emerging under conditions of extreme pressure and changing a planet’s geology, this means broadening the framework for what it takes to search for life on other planets. In fact, a research team led by Canadian astrophysicist Sara Seager (51) has shown in 2020 that some microbes can survive in an environment made up almost entirely of hydrogen – greatly expanding the range of planets on which life could be possible. The chemical processes brought about by microbes deep in the earth’s crust may further deepen the possibilities of this pursuit.

More urgent than the search for exoplanets on which life might be possible, however, is securing the existence of our own species – as early as 2027, global temperature is expected to drop by 1 percent, as the World Weather Organization (WMO) announced last week. 5 degrees Celsius higher than in pre-industrial times. That’s where Karen Lloyd’s research and microbes called chemolithoautotrophs come into play once again: Through years of research on volcanoes and hot springs, Lloyd was able to prove that these microbes in the soil bind to CO.₂ turns into carbonate minerals. So they eat CO so to speak₂ and turn it into rock. The research isn’t that far yet, however: A partial solution for our big CO₂A problem in our atmosphere that threatens to wipe out most of the life on our planet’s surface could literally be at our feet. KO to do this₂ but somehow moving into the depths.

Eco-friendly(re)s Gasoline, reduced radiation

Microbes do almost magical things in other ways, too—we’re surfacing from the depths of the earth’s crust for the next two examples: Last year, US biofuel experts at Berkeley Laboratory, a research institute funded by the US Department of Energy, built one. A breakthrough was achieved in fuel production. They turned Streptomyces microbes, which produce a molecule to repel fungi, into a biofuel. And not only is it more sustainable to produce than conventional gasoline, it also uses more energy and emits much less CO during combustion.₂ to the atmosphere. Microbes also help dispose of radioactive waste: In 2021, Spanish microbiologist Gemma Reguera of Michigan State University in the USA decoded the process by which a microbial species called Geobacter breaks down radioactive uranium. By adding electrons, on the one hand, it triggers a chemical reaction on which the bacterium feeds, on the other hand it mineralizes the residues, so to speak, regenerates the uranium so that it no longer emits in the environment.

There are almost no limits to the possible uses of little helpers. Unless they continue to be bothered by agriculture and air pollution. It’s time to protect microbes, which countless researchers have claimed based on the many studies in various specialty journals since this year.

Source : Blick