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Economic Importance of Protozoa and Mode of Infection

Protozoa are unicellular, microscopic, eukaryotic protists which are found in everywhere such as water; soil, on the body of plants and animals. They lack a cell wall and their size ranges from 5 to 250 micrometers.

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Economic Importance of Protozoa

In this article, we will discuss the Economic Importance of Protozoa, but before we have to know what is Protozoa?

Protozoa are unicellular, microscopic, eukaryotic protists which are found in everywhere such as water; soil, on the body of plants and animals. They lack a cell wall and their size ranges from 5 to 250 micrometers.

There are various Economic Importance of Protozoa which depend on the types of protozoa. Protozoa are divided into two groups based on their activities such as Beneficial Protozoa and Harmful Protozoa. Each of them contains unique importance such as;

Beneficial Protozoa

The Economic Importance of Beneficial Protozoa are;

Provide Foods

 Helpful in Sanitation

Symbiotic Protozoa

There are several symbiotic protozoa which lives within the gut of termite such as Trichonympha and Colonymphya etc. They digest the cellulose which is utilized by the host cell.

Control of insect

There are other protozoa which prevent harmful insects by persisting their bodies.

Commercial use/Industry

Skeleton of dead protozoa (Foraminifera and Radiolaria) immerse in sea & create oceanic ooze at the bottom part of ocean. These are solidified & covert into rock strata. Some of them are used as a filtering agent or used to make chalk and still, others are utilized for abrasives.

Building Material

The skeleton of protozoa which are getting deposits at the sea bottom they converted into the limestone rock over time. These limestones are used as Building Material. A common example of protozoa is Comerina which helps in the formation of limestone.

Oil Exploration

Skeletone of various protozoa often found in association with oil deposits. Such an example is the skeleton of Foraminifera and Radiolaria. Thus they help to find the exact location of oil.

Scientific Study

For the minute size and quick reproduction of protozoa, geneticists use them in laboratories to study the heredity and variations. Some of them also used in biological and medical researches. Such an example is; Tetrachymena geleii is used in nutritional research to check the effects of various foods and poison.

Harmful Protozoa

All the harmful or parasitic protozoa are found in plants, animals including man and responsible for various infectious diseases. These are harmful as well as useful species.

Pollution of Water

Some protozoa are important in water disinfection, while others are engaged in water contamination or pollution. The protozoa of fecal source refer to this category. Some free-living protozoa such as Uroglenopsis, also contaminate water by creating pungent and oily secretions with offensive odors, which provide unfit water for human consumption.

The free-living protozoa multiply in natural drinking water and make them unpalatable. An example of this type of protozoa is, Uroglenopsis which responsible for flashy odor like that of cod- liver oil. Peridinium release a smell which is resembling that of clam-shells.

Soil Protozoa

The soil contain different types of species of protozoa, which are feed upon the nitrifying bacteria. Thus they decrease their activity as well as decrease the concentration of nitrogen in soil which is given the nitrifying bacteria.

Destruction of Animals of Food Value

The excessive growth of dinoflagellates such as Noctiluca and Gonyaulax turns the ocean water red with their bodies. As a result, they perform a toxic reaction with the molluscs like clam oysters and mussels and make them unfit for eating by human beings.

Destruction of Wooden Articles

The termite’s gut contains some flagellates such as Trichonympha and Colonympha, which help them to digest the cellulose material. In absence of these flagellates termites will die or change their diet. Therefore, these indirectly influence the distraction of wooden articles and books.

Parasitic Protozoa

Parasitism is a relationship between two organisms where one organism lives at the expense of the other giving nothing in return. The first one termed as parasite and the other one known as host, on which the parasite lives.

There are present two types of parasites on the basis of their survival technique such as Facultative parasites, which can live for a long time without the host. The second one is obligatory parasites, these are cannot survive when separated from their host.

Pathogenic Protozoa

Those protozoa responsible for infectious disease are known as Pathogenic Protozoa. There are different class of pathogenic protozoa such as;

Types of Parasite

Based on the type and level of intimacy and the location of the parasites on their host cell, they are classified into two groups such as;

  1. Ectoparasites
  2. Endoparasites


Ectoparasites are live on the surface of the host cell. There are different types of Ectoparasites such as;


These types of parasites are live within the host body. There are present different types of Endoparasites which are classified based on their location;

Parasitic Protozoa Mode of Infection

There are differetn way by which parasitic protozoa reach new hosts such as;

  1. Active Migration: The epizoic parasites of aquatic hosts reach new hosts by this method. Example: Ichthyophthirius which actively comes out of the host i.e. fish and infects the other host.
  2. Direct Transfer: In this method the parsite infect when the it comes in direct contect with the other host. Example: Trichomonas vaginalis.
  3. Accidental Infection: When host accedently swallow the parasite contaminated food and water. Example: Conccidia, Entamoeba histolytica etc.
  4.  Infection by Intermediate Host: When vector ( Anopheles female mosquito, fly) suck blood they accedently take the blood-parasite like Plasmodium and Trypanosoma with them and transfer them to other host during a blood meal on other.
  5. Congential Transfer: The germinative infective, taking place at or before birth, may occur in several ways as placental transfer takes place in case of Plasmodium in man, ovarian transfer as takes place in Nosema in silkworm etc.



MN Editors. (May 7, 2021).Economic Importance of Protozoa and Mode of Infection. Retrieved from https://microbiologynote.com/economic-importance-of-protozoa-and-mode-of-infection/


MN Editors. "Economic Importance of Protozoa and Mode of Infection." Microbiology Note, Microbiologynote.com, May 7, 2021.


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