Types Of Microorganisms

                                              

               

   

Microbiology, study of microorganisms, or microbes, a diverse group of minute, simple life forms that include bacteria, archaea, algae, fungi, protozoa, and viruses. 

Types of microorganisms

The major groups of microorganisms—namely bacteria, archaea, fungi (yeasts and molds), algae, protozoa, and viruses.

1.  Bacteria (eubacteria and archaea)

Microbiology came into being largely through studies of bacteria. The experiments of Louis Pasteur in France, Robert Koch in Germany, and others in the late 1800s established the importance of microbes to humans. As stated in the Historical background section, the research of these scientists provided proof for the germ theory of disease and the germ theory of fermentation.

The organisms that constitute the microbial world are characterized as either prokaryotes or eukaryotes; all bacteria are prokaryotic—that is, single-celled organisms without a membrane-bound nucleus.

2.  Algae

Unlike bacteria, algae are eukaryotes and, like plants, contain the green pigment chlorophyll, carry out photosynthesis, and have rigid cell walls. They normally occur in moist soil and aquatic environments. These eukaryotes may be unicellular and microscopic in size or multicellular and up to 120 metres (nearly 400 feet) in length. Algae as a group also exhibit a variety of shapes. Single-celled species may be spherical, rod-shaped, club-shaped, or spindle-shaped. 

Algae also occur in colonies, some of which are simple aggregations of single cells, while others contain different cell types with special functions.

3.  Fungi

 Fungi are eukaryotic organisms that, like algae, have rigid cell walls and may be either unicellular or multicellular. Some may be microscopic in size, while others form much larger structures, such as mushrooms and bracket fungi that grow in soil or on damp logs. Unlike algae, fungi do not contain chlorophyll and thus cannot carry out photosynthesis. Fungi do not ingest food but must absorb dissolved nutrients from the environment. Of the fungi classified as microorganisms, those that are multicellular and produce filamentous, microscopic structures are frequently called molds, whereas yeasts are unicellular fungi.

4.  Protozoa

Protozoa, or protozoans, are single-celled, eukaryotic microorganisms. Some protozoa are oval or spherical, others elongated. Still others have different shapes at different stages of the life cycle. Like animal cells, protozoa lack cell walls, are able to move at some stage of their life cycle, and ingest particles of food; however, some phytoflagellate protozoa are plantlike, obtaining their energy via photosynthesis.  Protozoan cells contain the typical internal structures of an animal cell.

The amoebas (also amoebae) do not swim, but they can creep along surfaces by extending a portion of themselves as a pseudopod and then allowing the rest of the cell to flow into this extension.

5.  Viruses

Viruses, agents considered on the borderline of living organisms, are also included in the science of microbiology, come in several shapes, and are widely distributed in nature, infecting animal cells, plant cells, and microorganisms. The field of study in which they are investigated is called virology. All viruses are obligate parasites; that is, they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions. 

6.  Lichens

Lichens represent a form of symbiosis, namely, an association of two different organisms wherein each benefits. A lichen consists of a photosynthetic microbe (an alga or a cyanobacterium) growing in an intimate association with a fungus.

Lichens play an important role ecologically; among other activities they are capable of transforming rock to soil.

The phrase "small is powerful" is true and microorganisms are live examples of it & really, the wonders of life are always hidden in small things.