How many species of bacteria are known in the world?

1.Coliform bacteria.

The next time you sit on the toilet and can't get up and have constant diarrhea, think about it, the culprit could be your phone. Microbiologists at the University of Arizona concluded in a 2012 study that, on average, smartphones carry more bacteria than toilets.

Some experts say we need not be surprised. Because in general, there are fewer bacteria on human thighs than on the hands and mouth. However, even people with a hygienic fetish tend to clean toilets more often than mobile phones.

However, it's still hard to ignore the presence of coliform bacteria. Coliform bacteria are always present in the feces of human animals and in the soil of plants. Now, coliform bacteria are also unabashedly present on an individual's mobile phone.

Although small amounts of these bacteria won't make you sick, their presence means that other pathogens are lurking on your phone as well.

2.Colibacillus.

Like most of the bacteria listed in this article, E. coli is one of the bacteria we are afraid to avoid. However, the truth of the matter is that not all strains of E. coli are harmful to humans, and some strains are even beneficial to the human digestive tract.

E. coli bacteria are normally found in the human gut, and the presence of this bacterium on mobile phones means the presence of other contaminants. In addition, a strain of E. coli of the O157:H7 serotype may be present on the phone.

Although their presence is very rare, it is this pathogen that causes the occurrence of foodborne illness that we hear about in movies and local newscasts.

3.Staphylococcus aureus aureus.

Pyococcus aureus is another common bacterium, and its damage varies depending on the strain. Some strains can cause serious ** diseases such as staphylococcal infections. For example, methicillin-resistant Staphylococcus aureus can cause boils, and the bacteria are spread through contact.

Usually this germ spreads in hospitals, medical centers, etc., and the use of dirty mobile phones has undoubtedly accelerated the process.

In a 2009 study, Turkish microbiologists found that more than half of the 200 people they tested (52%) had their mobile phones contaminated with Staphylococcus aureus. Exposure to methicillin-resistant Staphylococcus aureus reached 38%.

1.Oral bacteria: treponema tartar.

Oral bacteria: treponema tartar.

Everyone has this little nuisance bacterium in their mouths, but if they grow out of control due to poor hygiene, it can wreak havoc on the gums. They live in a dark, moist environment between their teeth and gums, where they congregate. Treponema tartar is associated with Treponema pallidum, a bacterium that can cause syphilis.

2.Oral bacteria: Porphyromonas gingivals.

Oral bacteria: Porphyromonas gingivals.

Having periodontal disease is not a good thing, and the presence of Porphyromonas gingivalis in the mouth is also bad for health, which is a major bacterium that causes periodontal disease. Not only can Porphyromonas gingivalis cause inflammation, but it can also lead to antibiotic resistance, which is now common. In fact, they squeeze out bacteria that are good for your teeth and take their place.

Once Porphyromonas gingivalis gets out of control, it can eventually cause the gums to fall out of the teeth.

3.Oral bacteria: Viron cocci.

Oral bacteria: Viron cocci.

We can find this parasitic genus not only in the mouth, but also in the respiratory tract and digestive tract. They are one of the most common of the complex bacterial communities that exist in the human body, although some bacteria such as Velon spp.

There are about 200 species, of which about 80 live in the human mouth. Our body is a microbial factory, producing between 100 billion and 100 trillion bacteria every day. There are 10 billion microorganisms living on the surface of the intestine per square centimeter, and 10 million bacteria living on the surface of the intestine per square centimeter**.

The largest number of bacteria in the human teeth, throat and digestive tract is more than a thousand times more than the surface of the human body.

1.Coliforms, 2Escherichia coli, 3

Streptococcus, 4Staphylococcus aureus pyogenes, 5 molds, 6Yeast, 7

Clostridium difficile, 8Coagulase-negative staphylococci, 9Pseudomonas aeruginosa, 10

Corynebacterium.

How many of the 10 common bacteria have you seen?

At present, there are 4,760 known species of bacterial species in the world, and it is estimated that there are 40,000 species of bacterial species. Bacteria are divided into three categories according to their appearance: cocci, bacilli, spirobacteria.

Coocci, which are spherical or nearly spherical, and some are spearhead or kidney-shaped. The diameter of a single coccus is about about the same. Bacilli, the size, length, curvature, and thickness of various bacilli vary greatly.

Most of the bacilli contain foci of equal size, 2 5 μm in length and width. Large bacilli such as anthrax talk about the bacillus (3 5um, small such as Bacillus hare fever (. Most of the forms of the bacteria are straight rods, and some of them are slightly curved.

The two ends of the thallus are mostly obtuse and round, a few are flat at both ends like Bacillus anthracis, and some are thin at both ends such as Fusobacterium or the ends are enlarged and rod-shaped like Diphtheria. The arrangement is generally scattered, there is no certain arrangement form, occasionally in pairs or chains, and individual arguments are arranged in a special way such as fences or V, Y, and L!

The April 16, 1997 issue of Science reported that the largest bacterium ever discovered, the average diameter of this coccus is to millimeters, and the largest can reach millimeters, which is 100 to 300 times the diameter of a typical coccus of 1 micron, so that it is a million to 30 million times the size.

In April 1997, a Russian exploration ship obtained a specimen from a reef off the Atlantic coast of Namibia, Africa, which contained this large bacterium visible to the naked eye, so Heidi Schutz at the Planck Institute for Marine Microbiology in Berlin, Germany, together with a group of people from the University of Barcelona in Spain and the Woodshole Oceanographic Institute in Massachusetts, USA, named it the Namibia Sulphur PearlIn terms of size, traditional bacteria are like newborn mice and blue whales in the sea compared to this giant bacteria.

Sulfur pearls accumulate in the form of refining under the microscope, and in their natural state they survive in seafloor sediments with high concentrations of hydrogen sulfide, which is extremely toxic to animals, but it is the food of sulfur pearls, and it contains nitrates in the cell walls to oxidize hydrogen sulfide.

In extreme environments, the presence of some exotic microorganisms, such as archaea in hot springs at high temperatures Celsius, and the presence of bacteria on the seabed and ice in Antarctica, are not only exciting for those who study the origin of life, but also for biotechnology experts.

Whether the number of bacteria is so large that it is impossible to count is still unanimous in the scientific community.

Although some estimate that there are 100 billion species of microorganisms on the earth, and that there are 20 million to 1 billion species of microorganisms in the ocean, the number reaches 10 to the 30th power, accounting for more than half of the weight of marine life, there is currently no good way to count bacteria, so this number is not accurate. In fact, genetic sequencing technology relies on genetic sequencing technology to estimate that there are only millions of bacteria on the planet.

As of 2016, we have more than 13 000 bacteria and archaea validly named. Even if culture could not be made, a way to classify or nomenclature bacteria that did not rely on culture was found, and this is the international rule of "bacteriological code" that was implemented in 1980.

Under this international rule, the number of effective prokaryotic species and genera declared in the list has decreased from the original estimate of 30,000 to about 1,800 and 300, respectively. Since then, microbial taxonomists have been able to isolate and describe only a few hundred new species each year.