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What are Microorganisms?

Microorganisms or a microbe is microscopic organism. The study of microorganisms is called microbiology. There are various microorganisms types like bacteria, fungi, archaea, or protists. It doesn't include viruses and prions because they are classified as non-living. 

Microorganisms are minute, unicellular organisms that aren't visible to the naked eye. The reason they are called microorganisms is that you can only see them when you use a microscope. These organisms make up around sixty percent of the earth's living matter.

Microorganisms are also known as microbes. This term is used to describe several different life forms of different sizes and characteristics. 

Microorganisms are organisms that can be harmful as well as helpful. Some microbes can cause severe infections like spoiling food and other items. At the same time, others play an essential role in maintaining an ecological balance.

What are the Major Groups of Microorganisms?

Many different microbes or microorganisms are found in various places, including the human gut and skin. Here are the names of microorganisms: 

  • Bacteria: Bacteria are unicellular, microscopic microorganisms that have no nucleus. Their cell walls are made of peptidoglycan, which has a flagellum. The flagellum is responsible for the locomotion of the bacteria. Bacteria play a vital role in the survival of human beings. They are the ones who are responsible for breaking down nutrients in the digestive system into simpler forms. One of the bacteria, Rhizobium, is responsible for nitrogen fixation. It is also used for making antibiotics and can be used in agriculture as a pesticide.

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  • Fungi:  Fungi can be unicellular or multicellular, with walls that are made of chitin. They are heterotrophic and cannot make their food. Fungi comprise membrane-bound organelles. Some of the primary forms of fungi are mushrooms, yeasts, and mould. They decompose dead plants and animals and extract nutrients from them. A few of the fungi are harmful as they can cause a fungal infection like ringworms. At the same time, others are significant as they help in making penicillin.


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  • Viruses: They are the link or the connection between the living and the non-living. Viruses are non-cellular microorganisms that are composed of protein, nucleic acids, and lipids. These contain the core of the nucleotides, which is surrounded by a protein coat that can invade the living cells. Viruses are active inside the host cells and keep reproducing inside themselves by infecting the living cells.

  • Protists: Like the other microorganisms, protists are unicellular and microscopic organisms that are not plants or animals. Usually, they are either autotrophic or heterotrophic. Protists reproduce through binary fusion or budding. They supply humans with oxygen and recycle essential nutrients and make them available to other life forms.

  • Archaea: These unicellular microorganisms have a similar structure to bacteria. However, their cell wall is different from bacteria and contains unique lipids, which helps them survive in extreme conditions. Archaea are found in the human gut and skin.

Characteristics of Microorganisms

There are many types of microorganisms. Some characteristics are similar in some of them. Here are some of the features of microorganisms: 

  • When microorganisms are used in the large-scale production of alcohol, wine, and vinegar, it can be harmful.

  • Some microorganisms are known as pathogens that can cause diseases in humans, plants, and animals. 

  • Some organisms can spoil the leather, food, and clothing. 

Importance of Microorganisms

Microorganisms are present in almost all the places on earth. Despite their minute size, they are essential for the maintenance of life on this planet. Every organism has different activities, and they each have another way to influence life. 

Some of them are useful and helpful, like the microorganism, which helps fix atmospheric nitrogen into biologically functional forms. This helps in the formation of curd and recycling of dead material by degrading it into simpler substances. 

Uses of Microorganisms in Our Daily Life

There are many uses of microorganisms for use in many ways. Here are some ways in which we use microorganisms in our daily lives: 

Production of Dairy Products: Bacteria helps in the fermentation that helps make different forms of dairy products like curd, butter, cheese and buttermilk. Streptococcus is the type of bacteria that is used in the commercial production of dairy products. 

Bread Baking: A species of Streptococcus is added to the dough before you start making bread to bring about the fermentation. 

Organic Acids: Fungi is used in the preparation of many organic acids. Rhizopus and Penicillium are two fungi used in the fermentation of fruits and sugar-containing syrups. The acids derived and manufactured exploiting fungi are acetic acid, citric acid, lactic acid, and gluconic acid.

Fertility of Soil: Microorganisms play an essential role in maintaining the fertility of the earth. They are helpful in the composting process that in turn forms manure. When microorganisms are present in the soil, they help the ground aerate better and enrich the soil with nitrates and other essential nutrients, which allow the crops to have an abundant harvest.

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FAQs on Microorganisms

1. What are some examples of microorganisms?

Microorganisms examples are bacteria, archaea, fungi, viruses, and protists. Bacteria are found in nearly every organism in the world. Most bacteria are harmless, but there are some bacteria, pathogens which can cause diseases in humans and other animals. Archaea is another kind of microbe that is found on the planet. It's a unicellular prokaryotic organism whose cell walls contain Pseudopeptidoglycan. Another type of microbe is protist. It is a unicellular eukaryote that is not plants, animals or fungi. Algae and protozoa are kinds of protists. Fungi is another kind of microbe that is a eukaryote. Mushrooms resembling plants, yeast, and moulds are examples of microorganisms.

2. What are some of the uses of Microorganisms?

There are helpful as well as harmful microorganisms that are found around us. But we can use good microorganisms in many ways in our daily lives. For example, Bacteria helps in the process of fermentation, which can help you make curd, butter, cheese and buttermilk. If you want to make bread, the microbe that allows it is called yeast because it helps in the fermentation of the bread. Further, Fungi is essential to produce organic acids, such as acetic acid, lactic acid and citric acid. Besides, Rhizopus and Penicillium microbes are a form of fungi that help in the production of organic acids.