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The study of microorganisms or simply organisms that are not visible to the naked eyes is called Microbiology. Thus, Microbiology is a branch of science that deals with the scientific study of microbes. This includes organisms like bacteria, archaea, protozoans, algae, and so on. The organisms which are studied under microbiology may be unicellular or multicellular. But mostly these are microscopic organisms.  The study of these organisms is of utmost importance as they play various important roles in keeping the balance in nature. Also, they were the first kind of life forms on Earth from which other bigger and complex organisms developed.

Concepts of Microbiology

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Antonie Philips van Leeuwenhoek- a Dutch Biologist is known as the father of microbiology for his extensive research on microbes and contributions in the field. The basic concepts of microbiology are-

1. Maintaining target-specific practices and procedures under suitably controlled conditions which are called aseptic techniques

2. Following good microbiological lab practices.

3. Risk Assessment

4. Immediate reporting of spillage cultures

5. Use of disinfectants

6. Incubation

7. Dealing efficiently with accidents

Branches of Microbiology

Microbiology has two basic divisions- Pure microbiology and Applied microbiology. The study of microbiology is classified based on the taxonomy of the organisms. In a broader sense, pure microbiology is the scientific study of organisms whereas applied microbiology is the study of applications of microbiology, like biotechnology. Applied microbiology also refers to the fields in which the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms themselves are not studied as such in these routines but applied to sustain certain processes.

Various parts of pure microbiology and applied microbiology are as follows-

Pure Microbiology

• Bacteriology- The study of bacteria.

• Mycology –The study of fungi.

• Phycology- The study of photosynthetic eukaryotes like Algae.

• Protozoology – The study of protozoa or single-celled eukaryotes like the amoeba.

• Virology- The study of viruses, non-cellular particles which parasitize cells.

• Parasitology- The study of parasites (Only parasites which are microorganisms) which include pathogenic protozoa certain insects and helminth worms.

• Nematology- The study of nematodes (roundworms).

• Immunology- The study of the relationship between pathogens and their host.

Applied Microbiology

• Agricultural- Microbes interacting with agriculture

• Food- Microbes that spoil food or are related to foodborne diseases.

• Medical- Microbes that cause human diseases.

• Microbial- To develop industrial and consumer products.

• Pharmaceutical- Microbes used for pharmaceutical processes.


Microorganisms hold an important place in the environment. As they are important to human health and the economy. Few microorganisms even have many beneficial effects that impact our existence. While the other group of microorganisms are lethal and cause serious diseases. They are present everywhere in nature. Some of them can even survive extreme conditions. Be it extreme high or low temperature. Alkaline or acidic environments, some can even survive radiations up to some extent.

Types of Microorganisms

Some microorganisms are harmful to us and some are beneficial, depending on what we gain from them.

Harmful Microorganisms

Organic matter cannot decay on its own, it’s the predominant function of microorganisms. They are responsible for decay and decomposition of the organic matter. They are also responsible for spreading diseases or even causing them. They do not just infect human beings, but almost all other extant species in nature and even plants. Some of the disease-causing microorganisms are-

Bacteria: they cause pneumonia, bacterial dysentery, diphtheria, bubonic plague, meningitis, typhoid, cholera, and so on.

Virus: they cause diseases like Chickenpox, measles, mumps, German measles, colds, warts, cold sores, influenza, etc.

Protoctista: they mostly cause amoebic dysentery, malaria, in humans.

Fungi: ringworm, athlete’s foot, other fungal infections are caused by fungi.


Useful Microorganisms

Most Fungi are saprotrophic and bacteria are decomposers in nature. Thus, they have an important role in the ecosystem. They break down dead or organic waste matter and release inorganic molecules in nature which are nutrients for soil and plants. Green plants take up these nutrients which are in turn also consumed by animals, and the products of these plants and animals are again broken down by decomposers. Thus, they maintain a cycle in the ecosystem of returning the needed nutrients and taking the organic wastes and digesting them.

Some microbes like yeast are a single-celled fungus that is naturally found on the surface of the fruit. They are economically important in bread-making and brewing beer and also in the making of yogurt.

FAQ (Frequently Asked Questions)

1. What is the Importance of Microorganisms?

Microorganisms have various applications in our day to day lives. They are economically important as they are used in various industrial processes and manufacturing healthcare products. They are utilized for making various foods, treating wastewater, creating biofuels, and a wide range of chemicals and enzymes.  They are very important to agriculture through their roles in maintaining soil fertility and in decomposing organic matter. They are also used to produce energy, for example- in biogas reactors.

2. What is Microbiology?

Microbiology is a branch of science that deals with the scientific study of microbes. This includes organisms like bacteria, archaea, protozoans, algae, and so on. The organisms which are studied under microbiology may be unicellular or multicellular. But mostly these are microscopic organisms that are, we cannot see them with naked eyes.