Where do Microorganisms Live?

Microorganisms (also called microbes) are living organisms that can be only seen through a microscope. Microorganisms can be unicellular (example: bacteria) or multicellular (example: fungi). Microorganisms are present everywhere, and they can survive in all types of environments. They are also present in the bodies of different animals and plants. Some microorganisms are useful for plants, animals, and humans, whereas others cause diseases. Viruses are sometimes classified as microorganisms, but viruses are just genetic materials that can live only in the bodies of other organisms. Examples of microorganisms include amoeba, bacteria, etc.

Classification of Microorganisms

Microorganisms are classified into four major categories. They are:

1. Algae
2. Bacteria
3. Fungi
4. Protozoa

Algae

Algae are a group of oxygenic, phototrophic, and eukaryotic microorganisms. They can exist in different ecosystems like fresh water or marine, deserts, snow, and ice. Algae can exist as single cells (example: Chlamydomonas) or together in chains (example: Spirogyra). Green algae have chlorophyll pigment that can generate oxygen through photosynthesis. Algae are used as food in different ways. They are an important source of protein and energy. Examples are Chlamydomonas, Spirogyra, Spirulina (blue-green algae), etc.

Bacteria

Bacteria is a single-celled organism that comes in various shapes like spheres, rods, and spirals. Some bacteria are pathogenic and cause diseases, whereas others are useful to plants and animals. Bacteria are classified into five groups based on their shapes: spherical (cocci), rod-shaped (bacilli), spiral-shaped (spirilla), comma-shaped (Vibrios), or corkscrew-shaped (spirochaetes).

Fungi

Fungi can be unicellular (yeast) or can be complex multicellular (mushroom) organisms. Fungi mostly live on land, mainly in soil or with plants. Some fungi are parasites to plants and cause diseases. Very few fungi cause diseases in animals and humans. Examples are Bread mold, Penicillin, Aspergillus, etc.

Protozoa

Protozoa are a group of single-celled eukaryotic organisms that are either free-living or parasitic. They cause diseases like dysentery and malaria. Examples are Amoeba and Paramecium.

Viruses are also microscopic, but they are not considered microorganisms. This is because viruses are just genetic materials, and they need the help of other organisms like plants, animals, or other microbes for survival and reproduction. Viruses cause diseases like cold, cough, influenza, polio, chicken pox, etc.

Where do Microorganisms live?

Microorganisms are found everywhere, in every corner you can imagine. They are found on your palms, books, pen, table, food, mobile phones, soil, hair, and even in your intestines. There may not be any possible place where microbes do not exist.

Microorganisms are found in all types of environments. They adapt to the environment in which they live. They can reproduce and grow in environments where other organisms cannot survive. They live in water, soil, and air. They can survive in extreme conditions like ice-cold areas, hot springs, equators, deserts, polar regions, oceans, and marshy lands. They are also found inside other living organisms like plants, animals, and humans. Millions of microbes are found in the human body. Some microbes cause diseases, whereas others are useful for us. Some microorganisms live freely, whereas others grow on other living organisms. 

Every microbe cannot survive in all types of habitats. Each type of microorganism evolves and adapts itself to a narrow range of conditions. Microbes constitute the majority of the biodiversity of the earth. There can be millions of microorganisms in extreme climatic conditions which are undetermined. Physical and chemical factors like temperature, pH, and salinity determine the type of microorganisms that can thrive in such a habitat. Microorganisms are a major part of the ecosystem and are very important for ecological balance.

Microorganisms as Friend

• Microbes (Rhizobium bacteria) present in root nodules of leguminous plants help in nitrogen fixation.
• Microbes present in soil help in the decomposition of organic matter and convert it to manure.
• Microbes present in milk (Lactobacillus) help in the conversion of milk to curd.
• Microbes present in the intestines of humans and animals help in digestion.
• Microbes (yeast) help in making bread and cakes.
• Microbes present in batter help in the souring of dosa batter.
• Microbes are useful in the large-scale production of vinegar, alcohol, and wine through fermentation.
• Microbes are used in the production of antibiotics such as Streptomycin, tetracycline, erythromycin, etc.

Harmful Impacts of Microorganisms

• Microorganisms that cause diseases are called Pathogens.
• Some microbes cause communicable diseases which spread from an infected person to a healthy person through food, water, and air. Example: chicken pox, common cold, cholera, etc.
• Plasmodium parasite spreads malaria through female Anopheles mosquito.
• Bacteria cause diseases like tuberculosis, cholera, and typhoid in humans.
• Viruses cause Measles, Polio, and chicken pox.
• Anthrax bacteria cause dangerous human and cattle diseases.
• Microorganisms cause diseases in plants like citrus canker (caused by bacteria), and rust of wheat (caused by fungi).
• Some microbes spoil food and cause food poisoning.

Frequently Asked Questions

Question 1: What are the four major categories of microorganisms?

Answer: 

1. Algae
2. Bacteria
3. Fungi
4. Protozoa

Question 2: What are the diseases caused by protozoa?

Answer:

Dysentery, Malaria, African trypanosomiasis, Chagas disease, Leishmaniasis, and Toxoplasmosis.

Question 3: Where do Microorganisms live?

Answer:

Microorganisms are found in all types of environments. They live in water, soil, and air. They can survive in extreme conditions like ice-cold areas, hot springs, equators, deserts, polar regions, oceans, and marshy lands. They are also found inside other living organisms like plants, animals, and humans. 

Question 4: What are algae, and where are they found?

Answer: 

Algae are a group of oxygenic, phototrophic, and eukaryotic microorganisms. They can exist in different ecosystems like fresh water or marine, deserts, snow, and ice. 

Question 5: Why viruses are not considered microorganisms?

Answer:

Viruses are also microscopic, but they are not considered microorganisms. This is because viruses are just genetic materials, and they need the help of other organisms like plants, animals, or other microbes for survival and reproduction.

Question 6: Can microbes survive in extreme conditions?

Answer:

Microorganisms can survive in extreme conditions like ice-cold areas, hot springs, equators, deserts, polar regions, oceans, and marshy lands. There can be millions of microorganisms in extreme climatic conditions which are undetermined. Every microbe cannot survive in all types of habitats. Each type of microorganism evolves and adapts itself to a narrow range of conditions. Physical and chemical factors like temperature, pH, and salinity determine the type of microorganisms that can thrive in such a habitat. 

Question 7: What are the diseases caused by microorganisms?

Answer:

• Microorganisms cause diseases like chicken pox, common cold, cholera, malaria, polio tuberculosis, and typhoid in humans.
• They cause diseases like citrus canker, rust of wheat, and yellow vein mosaic of bhindi (Okra) in plants.
• They cause anthrax and Foot and mouth disease in cattle in animals.