What are bacteria?

December 19, 2014
What are bacteria?

Many people think that bacteria and microbes are the same thing that these words are synonymous. However, this is not entirely true. Let's understand what bacteria are, how they differ from microbes, what their structure is and how they were discovered.

Bacteria and microbes: the difference

Bacteria are a group of prokaryotic microorganisms. At the moment, about 10 thousand bacteria have been studied, but it is assumed that there are much more of them - more than a million.

Microbes (microorganisms) are microscopic living organisms, which include prokaryotes (archaea, bacteria) and eukaryotes (protists, some fungi).

Thus, it turns out that microbes are a much broader concept compared to bacteria, therefore, it is wrong to consider these words to be fully-fledged synonyms of each other.

Bacteria structure

Most bacteria consist of a single cell. The following forms of bacteria are distinguished:

  • round (cocci);
  • convoluted (spirilla, vibrio);
  • rod-shaped (pseudomonads, bacilli);
  • rare forms - forms of cube, tetrahedron, stars, O- and C-shaped.

The composition of a bacterial cell consists of a membrane, nucleotide and ribosomes.Around the cell there is a protective shell consisting of several layers: the wall, the capsule and the sheath. Also, the bacterial cell has surface structures - these include the villi and flagella, which are necessary for the movement and fixation of the bacteria.

From the history of the study of bacteria

  • The first who saw the bacteria in a microscope and described them was naturalist Anthony van Leeuwenhoek. It happened in 1676.
  • The term "bacterium" was introduced by Christian Ehrenberg in 1828.
  • In the 50s of the XIX century, Louis Pasteur began to study the metabolism and physiology of bacteria.
  • A detailed study of the structure of bacteria began in the 1930s, when the electron microscope was invented.