Amazing bacteria

Humans have always tried to find the best way to store information. Many millennia ago, we started sharing our ideas through paintings inside caves. Then came books and computers, and we recently learned that diamonds are great data storage devices. But then bacteria entered the game when scientists managed to insert information into them. That’s right: Some microbes can transport text, videos, and images in their bodies, turning them into living computers.It happens that when bacteria destroy an enemy virus, they store small parts of the virus’s DNA inside their own bodies. In this way, microbes learn to recognize similar threats in the future. Taking advantage of that mechanism, scientists from Harvard University first cultivated a population of 600,000 Escherichia coli bacteria. Then, they coded an image of a human hand and a short video of a galloping horse into a DNA strand.[5] And finally, the E. coli received electric shocks so that they activated their defense mechanism and thus absorbed the man-made DNA.

Cancer is the second-leading cause of death around the world. In 2018, almost ten million people died due to this type of disease, and the annual number of cancer cases is expected to reach 23.6 million by 2030. Well, that could change, because scientists have discovered a method to radically fight cancer. And you guessed right, the method involves bacteria.In February 2018, a group of researchers from the University of California discovered that the bacterium Staphylococcus epidermidis has anti-cancer powers. This microbe is commonly found in healthy human skin. Upon careful analysis, scientists noted that S. epidermidis produces a chemical compound similar to a certain DNA component. When the researchers tested the substance (called 6-HAP) in the laboratory, they realized that it stopped DNA production. Specifically, the chemical prevented cancer cells from multiplying further. However, 6-HAP had no effect on normal cells, since certain enzymes within them deactivated the chemical.[11]The scientists injected 6-HAP into a group of mice, while another group was left unaffected. The animals were then exposed to high doses of UV radiation. The results showed that although all mice developed cancer, the tumors of the mice with 6-HAP were 60 percent smaller than those of the normal mice. The researchers proceeded to repeat the experiment, this time by spreading S. epidermidis bacteria on the backs of mice instead of injecting them. Even in that way, the mice covered with the microbes developed only one tumor after the radiation dose, while the normal mice had up to six of them. Although more research is still needed on these creatures, it is believed that S. epidermidis could be used in the future to prevent multiple cancers—besides skin cancer.

If everything goes well, humans can expect to live a little over 70 years on average. Some reptiles can live close to 200 years, while a few trees have lived around 5,000 years. But all that is just a blink (figurative, of course) for the oldest bacteria in the world. Indeed, in 2007, researchers discovered bacteria more than half a million years old, which were still alive.A team of scientists from the University of Copenhagen (Denmark) obtained samples of these bacteria in layers of ice in Canada, Russia, and Antarctica. It is estimated that the microbes have been alive for about 600,000 years, and when scientists looked at their DNA, they were surprised to see that it was almost intact. This is something extremely unusual for creatures of that age, since DNA starts to break down after some time. To survive for millennia, many microorganisms enter a state of almost total inactivity, but even so, their DNA will continue to suffer great damage.The key to the long life of these old bacteria lies in their amazing ability to self-repair their DNA. Instead of becoming lethargic and suspending its functions to survive, this particular creature keeps a small part of its metabolism active. In this way, the body of the bacterium will keep constantly repairing its own DNA while waiting for the environment to become more favorable for reproduction.There have been other reports of even older living bacteria, such as 250-million-year-old bacteria trapped in salt crystals. However, these reports remain unconfirmed, and it is speculated that the samples were contaminated with modern microbes while in the laboratory. By contrast, the 600,000-year-old bacteria are authentic, since the researchers made sure to avoid any form of contamination during the tests.[10]

In the early 1980s, scientists found the first known hyperthermophilic organisms, microscopic beings capable of living and reproducing at temperatures close to 100 degrees Celsius (212 °F). But it happens that most of these microorganisms belong to the Archaea domain, a group distinct from bacteria and discovered in the late 1970s. However, some hyperthermophilic bacteria have also been discovered, and their abilities make them more durable than most life on Earth.The genus Aquifex comprises bacteria capable of reproducing in underwater thermal vents and hot springs, at temperatures up to 95 degrees Celsius (203 °F). Just to get an idea, a human body submerged in that water would begin to boil until dissolving in a matter of hours. And even so, Aquifex can live in such an environment without difficulty, even at temperatures above 100 degrees Celsius (212 °F), which makes them the most heat-resistant bacteria of all.As if that were not enough, Aquifex are also aerobic—that is, they can breathe oxygen. Although these microbes only tolerate low oxygen concentrations, they are among the few known aerobic hyperthermophilic bacteria. If the environment does not have oxygen, Aquifex can also breathe nitrogen. But the most impressive ability of these microorganisms is that they produce water as a byproduct while breathing.[9] For this reason, the bacteria earned the name Aquifex, which means “water-maker.”

The superpower of this bacterium gives it the ability to potentially erase all plant life on Earth, so Klebsiella planticola earns the prize for the supervillain of this list. Klebsiella bacteria are present in the roots of almost every plant on Earth. These creatures are responsible for decomposing dead plants, thus cleaning the soil of organic waste.German scientists took a sample of K. planticola bacteria and genetically modified them so that, by decomposing plants, they produced fertilizer and ethanol at the same time. A bacterium of this type would be easy to sell for agricultural and industrial uses, so in the early 1990s, it was planned to test K. planticola in the fields.However, in order to test its effectiveness, a team at Oregon State University conducted a laboratory experiment with a sample of fertile, sown soil. One part of the soil was filled with the original K. planticola, while the modified bacteria were placed in the other part. The results showed that although the seeds germinated in both soils, all plants in the section of the modified microbes were dead after a week.[8]The modified K. planticola produced 17 times more alcohol in the soil than plants could tolerate. In addition, plants use fungi to feed on soil nutrients, but the ethanol-producing bacteria increased the presence of worms that eat those fungi. So the plants not only died of poisoning but also of starvation.Adding to its evil characteristics, it was confirmed that the modified K. planticola bacterium was able to survive in soil for a long time, unlike other modified bacteria. In the end, the “killer” K. planticola was not commercialized. But it was contended (albeit disputed) that had it been released in the fields, this bacterium would have ended up annihilating all plant life on a continental scale.

Namibian sulfur pearl Thiomargarita Namibiensis, tiny giant

Photo: Sciblogs
Among the superheroes from the fictional universe of Marvel, there are several characters at once who can grow to the size of a multi-story building in a matter of seconds. So far, no real person is capable of something like this, but there are bacteria that have learned to increase in size with the “power of thought” alone, almost like comic book characters. These are the smallest and at the same time the largest microorganisms on Earth.
Thiomargarita namibiensis is considered the largest bacterium in the world, as it is 3 million times larger than any average bacterium. It was first discovered in 1997 off the coast of Namibia, and this microbe can grow up to 0.75 millimeters in length, which is why it can even be seen with the naked eye. The species was discovered by biologist Heide Schulz, and in his report he wrote something like this: “In terms of size, comparing an E. coli cell with a Thiomargarita namibiensis cell is like comparing a newborn mouse with a blue whale.”
The extremely large size of the Namibian Sulfur Pearl is due to its digestive system. It uses nitrates and sulfides for energy, and since their environmental concentration is not low enough for this microorganism, a hungry bacterium often has to accumulate as much nitrate in its body as possible. Thus, almost 98% of the volume of a giant microorganism is nitrate reserves, which are stored in an organelle in the very center of the bacterium.Outwardly, Thiomargarita namibiensis looks like a common white speck, since it also stores many sulfur granules. It is worth noting that due to the presence of sulfur in these microbes, their populations are of great benefit to the seawater in which they live. These bacteria literally purify water bodies, and in this way they are of great help to marine life. Thiomargarita namibiensis bacteria tend to form clusters with the help of mucus, and such clusters often resemble strands of microscopic white balls, like beads, for which the microbe gets its name Namibian sulfur pearl.

Magnetotactic bacteria, living magnets

Photo: Nature
Magnetism is an amazing superpower! Perception of electromagnetic fields, control of metallic objects and movement in space simply due to the magnetic field of our planet - all this sounds very tempting, but also absolutely impossible for mere mortals. However, this does not mean that there are no other creatures in the world who can do it. In particular, magnetotactic bacteria have already mastered all these skills quite a long time ago, becoming real living magnets.
A magnetotactic bacterium is a microorganism that can absorb iron oxide molecules and combine them to form tiny organelles called magnetosomes. These magnetic granules are 100,000 times smaller than a grain of rice, so a lot of them fit inside the bacterium. It is these tiny internal magnets that allow unusual microorganisms to feel the Earth's magnetic field and choose a direction, depending on where there is more food. And this is just the beginning...
Magnetotactic bacteria live mainly in swamps and other waters with low oxygen concentration, and therefore they constantly have to move in search of a more satisfying place. However, sometimes the sediment at the bottom of a stagnant reservoir is so dense that this microbe can no longer cope with the help of its flagellum alone. That's when the secret superpower starts up - with the help of its magnetosomes, the bacterium enters the mode of interaction with the Earth's magnetic field, which helps it get out of the trap. By the way, to remove these bacteria from the human body, scientists have developed a technology that also relies on their magnetism. Experts have learned how to saturate magnetotactic bacteria with magnetosomes, and then kill them with "magnetic heating." Perhaps in the future we will be able to use these microbes and their magnetosomes to fight contagious viruses on a large scale.

Caulobacter Crescentus, super sticky bacterium

Photo: Yves Brun, Indiana University
If you want to unstick a gecko from the wall or ceiling, on which these creatures run so talentedly, you will have to sweat a lot. You may not even be up to the task... However, the gecko's unique tenacity cannot match that of a bacterium called Caulobacter crescentus. Here is a real micro version of Spider-Man! This bacterium has a cohesive force that is 7 times stronger than that produced by the legs of a gecko, and it is also 3-4 times “stronger” than commercial superglue.
Caulobacter crescentus is found almost everywhere - in any environment, in any reservoir and in any water (salt, fresh, tap). This microbe moves with the help of an appendage called a flagellum until it finds a comfortable place for itself, where it remains to live. When the ideal home is found, the bacterium simply sticks to its surface with thin extensions called pili or fimbriae. When the comfortable position is finally occupied, the bacterium secretes a sugary adhesive substance that immediately and firmly adheres the microorganism to the chosen object.
Scientists conducted a series of experiments and found that the "superglue" produced by this unique bacterium has an adhesive force of 703 kilograms per square centimeter. In other words, a small piece of this substance could support an entire elephant or several cars if they could be hung above the ground. Because the bacterium Caulobacter crescentus lives in a very nutrient-poor environment, scientists believe that its superglue also helps it to forage. The researchers are convinced that such a sticky substance has an incredible practical potential that people in the future could use to create the strongest building materials or for medical purposes, for example, during operations.