Beijing time on December 13th, according tomedia reports, is breathing and reading this article of you, at this moment is benefiting from bacteria. From the oxygen we breathe, to the nutrients our stomachs absorb from food, it’s all thanks to the bacteria that continue to thrive on the planet. In our bodies, the number of microorganisms, including bacteria, is 10 times that of human cells, which makes us more like a collection of microbes.
Only recently did scientists begin to fully understand these microbes and their effects on the health of the earth and the human body. Historical studies show that our ancestors used bacteria to ferment food and drink, such as beer and bread, many centuries ago.
It was not until the 17th century that humans began to look at bacteria up close. Curious Anthony Van Levein-Huck discovered the bacteria while examining a sample of plaque between his teeth. In his work, he describes the colonies on his white teeth as “a little white matter, about as thick as the ‘batter'”, with poetic strokes. He placed the samples under a composite microscope and found that the microbes were moving, and they were alive!
In fact, bacteria are the Earth’s “rule changers” who create the air we breathe and play a key role in creating the Earth’s home.
In this article, we’ll give you a full picture of these microbes. They are small, but they have a significant impact on human history and the environment, both good and bad, and some aspects that we do not fully understand. First, we’ll tell you that bacteria are different from other types of life.
Basics of bacteria
Bacteria are protonuclear organisms, and they do not have the nucleus of human, animal, and plant cells.
How can we know so much about bacteria if they can’t be seen with the naked eye?
Bacteria typically range in size from 1 micron (one-millionth of a meter) to several microns. Scientists have developed powerful microscopes that allow bacteria to zoom in, giving us a glimpse into the inner workings of bacteria and comparing them with other life forms such as plants, animals, viruses and fungi.
Cells are the cornerstone of life, and genetic information about humans, animals, and plants is contained in membrane-like nuclei. These types of cells are called eukaryotes and have specialized organelles, each with a unique function to maintain cell function and health.
However, bacteria do not have cell nuclei, and their genetic material or DNA floats freely within the cell. They also have no organelles, and have different ways of breeding and exchanging genetic material. Such cells are classified as pronuclear cells.
In addition to basic classification, the scientists divided the bacteria into different camps based on the following points:
(1) whether it can survive and reproduce in an environment with (or without) oxygen;
(2) the shape of bacteria, including rod-like (spore), ring-like (cocci) or spiral (helicobacter);
(3) Gram-negative bacteria and Gram-positive bacteria. This is based on the classification of bacteria according to staining test, can understand the composition of extracellular protective film;
(4) How bacteria move and find direction in the environment (many bacteria have whiplash, and this tiny structure can drive them around the environment).
We call the study of all different types of microorganisms, including bacteria, geriates, fungi, viruses, and protozoa, microbiology, a discipline that is accumulating a growing knowledge of bacteria and other microorganisms.
Some tiny organisms similar to bacteria are now classified as archaea. In the past, these microorganisms were classified as protonuclear organisms along with bacteria, but after learning more about them, researchers now list them as one domain in a three-domain system (the ancient bacterial domain, the bacterial domain, the eukaryotic domain).
Energy sources (and gas by-products)
Like humans, plants and animals, bacteria need food to survive.
Some bacteria are self-contained organisms, which means they use basic inputs such as sunlight, water and chemicals from the environment to make food (in the case of blue bacteria, they have been using sunlight to make oxygen for some 2.5 million years). Other bacteria are called heterodox because they can feed on existing organic matter, such as deciduous leaves on forest floors, to get energy from them.
In fact, what appeals to bacteria can be repugnant to us, from leaking oil to by-products of nuclear reactions, from human-made waste to naturally decaying organisms, bacteria thrive in a variety of substrates.
On the other hand, bacteria’s preference for specific food sources can also benefit humans. Italian artists, for example, use bacteria to digest too many layers of salt and glue, extending the lives of priceless works of art. The ability of bacteria to recover organic matter is also widely used, especially considering that they themselves play an important role as recyclers on the Earth’s surface, including soil and water.
In your daily life, you may be familiar with the smell of bacteria when they consume energy. They break down our leftovers, absorb nutrients, and release gas by-products. At this point, your trash can will smell bad. However, this process does not stop there. Your gut bacteria also release foul-smelling gases (mainly methane) during digestion, and yes, the bacteria are responsible for some of your awkward moments.
A big family.
Whenever given the chance, the bacteria grow and form colonies. If food and environmental conditions are right, they multiply and form a sticky polymer called a biofilm (also known as a bacterial membrane) that is present on a variety of surfaces, from rocks in streams to molars in your mouth.
This biofilm has both advantages and problems. On the one hand, they allow bacteria to form mutually beneficial communities in nature; For example, doctors who treat patients with medical implants and equipment pay special attention to biofilms because these surfaces are highly conducive to bacterial growth. Once formed, biofilms produce toxic and even fatal by-products to the human body.
Like people in cities, cells in biofilms communicate with each other by sending messages and sharing information about food availability and potential dangers. It’s just that bacteria don’t call their neighbors, but instead send information to nearby friends through chemicals.
Of course, bacteria are not afraid to live alone. In fact, some species have developed ways to survive in harsh environments. When food is left short, or environmental conditions become worse, these bacteria protect themselves by creating a hard shell called endogenous spores (also known as spores, internal spores), leaving cells dormant to preserve the bacteria’s genetic material.
Some scientists have even found bacteria in time capsules placed 100 years ago, and scientists have discovered bacteria dating back 250 million years. All this suggests that bacteria can keep themselves for a long time.
Now that we know that bacteria become “colonists” whenever they have the chance, how do they “colonize” by splitting and breeding?
The reproduction of bacteria
How do bacteria produce colonies? Like other forms of life on Earth, bacteria need to replicate themselves in order to continue. Although humans and other organisms do this by sexual reproduction, the situation with bacteria is different.
First, let’s discuss why diversity is a good thing.
Life experiences natural selection, or certain chosen forces in a particular environment, that will allow a certain type of life to thrive and reproduce more. Genes are the basic unit that guides cells to do what – whether your hair turns brown or black, or whether your eyes turn brown or blue. The genes you get from your parents form a good combination. In addition, sexual reproduction can lead to mutations or random changes in DNA, resulting in diversity. The greater the genetic diversity, the more likely it is that organisms will adapt to environmental constraints.
For bacteria, reproduction is not a problem of the right kind and settling down; it simply replicates its own DNA and divides into two identical cells. This process is called binary fission, in which a bacterium copies its own DNA and transfers genetic material to both ends of the cell, dividing into two cells.
Because the cells produced by this mode of reproduction are genetically identical to the original cells, they are not the best way to create a diverse gene pool.
So how do bacteria get new genes?
In fact, bacteria use clever methods to do this, eventually achieving gene-level transfer, i.e. exchanging genetic material with other organisms without breeding. Bacteria have several methods of gene-level transfer, one relying on other microorganisms and bacteria to obtain genetic material from an extracellular environment (through plasmids) and the other through viruses that host bacteria. Once infected with a new bacteria, the virus leaves the genetic material of the bacteria before it.
Swapping genetic material gives bacteria a flexible adaptability, and some bacteria are more adaptable when they feel stress changes in the environment, such as food shortages or chemical changes. A better understanding of how bacteria adapt to the environment is important for understanding and combating bacterial resistance to antibiotics. Bacteria exchange genetic material so often that previously effective treatments may not work next time.
Understanding bacteria on a larger scale, our problem is not “where the bacteria are”, but “where the bacteria are.” They are almost everywhere on earth. We can’t fully grasp the number of microbes on Earth at once, including bacteria and ancient bacteria, but some estimate that it’s about 5 x 10 x 28!
Determining how many types of bacteria there are, or how many types can be classified, remains difficult. It is estimated that there are currently about 30,000 officially identified bacterial species, but scientists are still learning to increase their knowledge base. The researchers say we haven’t touched on the amount of fur in the real bacterial species.
In fact, bacteria have been around for a long time, and they form some of the earliest known fossils dating back 3.5 billion years. Scientific evidence suggests that between 2.5 billion and 2.3 billion years ago, blue bacteria began to produce oxygen in the world’s oceans, forming the Earth’s atmosphere and providing enough oxygen for many lives.
Bacteria can survive in air, water, soil, ice and extreme heat; they can live in plants, even in our intestines, on our skin, and on the skin of other animals.
Some bacteria are extreme microbes, which means they can withstand extreme environments, either very hot or very cold, or lack the nutrients and chemicals that are usually related to life. The researchers found bacteria in the Mariana Trench, the deepest part of the Earth’s oceans, and in underwater hydrothermal vents and glaciers.
However, the pleasure of discovering extreme bacteria is not just for researchers in the field. Visitors can also see the beautiful landscapes created by these bacteria in places like the Opalescent Pool in Yellowstone National Park in the United States.
Bacteria in space
Some bacteria that do not normally have a negative impact on human health may be more likely to infect astronauts. To better study the effects of space flight on bacteria, NASA launched the space shuttle Atlantis in 2010 and 2011, sending microbes that would normally cause treatable infections on Earth into space. The researchers found that the bacteria were able to form communities in ways not found on Earth. The results give researchers a better understanding of improving the health of astronauts (and people on Earth).
Bad bacteria (for humans)
Although bacteria have important contributions to human and earth’s health, they also have a dark side. Some bacteria are pathogenic and can cause serious diseases.
Throughout human history, some bacteria have been notorious for causing anxiety in the public eye. Take the plague, for example. The bacteria that caused the plague was Yersinia pestis, which historians believe not only killed more than 100 million people, but also shaped history and even led to the collapse of the Roman Empire. Until antibiotics or other drugs that can treat infections, it has been difficult for humans to stop the bacteria from spreading.
Even today, these pathogenic bacteria are still weighing heavily on our hearts. Because of antibiotic resistance, existing treatments can fail a range of bacteria that cause diseases ranging from anthrax, pneumonia, meningitis, cholera, salmonella and streptococcal laryngitis to E. coli and staphylococcal infections.
The case of Staphylococcus aureus is particularly evident. The bacteria is responsible for staphylococcus infections. The drug-resistant Staphylococcus aureus, known as the “superbug,” poses serious problems for hospitals and medical facilities, where patients are more exposed to medical devices and ureters.
Earlier we discussed natural selection and how some bacteria have more diverse genes to help them cope with changes in the environment. If you are infected with a disease that is different, antibiotics may kill most of the population, but also provide room for a small number of individuals not affected by antibiotics to reproduce and take root. That’s why doctors recommend staying away from antibiotics, unless you really need them.
Biological weapons is another frightening issue in the discussion of “bad bacteria”. In some cases, bacteria can be used as weapons, including for anthrax scares or for adding bacteria to aerosol sprays.
It’s not just humans that are attacked by bacteria. In fact, bacteria even have an appetite for the sinking Titanic. A bacterium called Halomonas titane can corrode titanic metal.
Bacteria and Dental Health
There’s something sticky on our teeth, called dental plaque, which is actually a biofilm of bacteria. If left unchecked, these bacteria can erode the enamel of the teeth and eventually lead to tooth decay. Archaeologists study not only human skulls, but also teeth to understand human eating habits and susceptibility to disease in different historical periods.
Let’s take a moment to understand the benefits of bacteria. After all, these microbes bring us delicious foods such as cheese, beer, sour dough and other fermented foods. They are also the unsung heroes behind medicine, promoting the improvement of human health.
We also want to thank the bacteria that shape the course of human evolution. Scientists are collecting more information from our microbiome, especially those in the digestive system, mainly in the gut. Studies have shown that bacteria and the diversity and new genetic material they bring to the human body enable humans to adapt and utilize new sources of food that were previously unusable.
We can look at it this way: bacteria are “working” for you on your stomach and gut surface, and when you eat, bacteria and other microbes help you break down food and absorb nutrients from it, especially carbohydrates such as corn, potatoes, bread, and rice. The more bacteria we ingest, the greater the diversity of the microbiome in the body.
While scientists’ understanding of the human microbiome is at best in fancy, there is evidence that the lack of certain microorganisms and bacteria in the body may be related to a person’s health, metabolism, and susceptibility to allergens and diseases. Preliminary studies of mice showed that metabolic diseases such as obesity were associated with the diversity and health of the microbiome, unlike the traditional “calorie intake and consumption” view.
Fecal transplant research is also at an early stage, but looks promising in treating certain gastrointestinal diseases. Probiotics are a class of microorganisms considered to be beneficial to health and are currently being studied, but so far there has been no general recommendation sediton for probiotics.
In addition, in the development of scientific thinking and human medicine, bacteria have changed the game. The Koch’s Law, established in 1884, is a set of research thinking that determines the causal relationship between disease and microorganisms, and the researchers used it to establish the pathogens of anthrax and nodules.
In addition to playing an important role in disease theory, bacteria make other contributions. For example, scientists who study bacteria stumbled upon penicillin, an antibiotic that saved countless lives. More recently, scientists have used bacteria to discover a simpler way to edit the genomes of organisms, which could revolutionise medicine. Researchers have modified some bacteria to be beneficial to human health in many ways, including the production of insulin used to treat diabetes.
We are just beginning to understand and exploit bacteria. (Any day)