Microbes are tiny living creatures which are invisible to the naked eye. Microbes are also known as microorganisms or microscopic organisms as they could only be seen under a microscope. Certain microbes could cause severe infections and disease that even result in death and others are the beneficial ones and harmless to our lives. They played a key role in the evolution of the planet earth. The most common microbes include  Bacteria, Fungi, and Viruses. Let us know in detail about each microbe.




They are single-celled prokaryotic microorganisms that are classified into five groups based on their shapes and are classified into two groups based on their staining properties. Bacteria are both beneficial and harmful to human beings. There are millions and billions of bacteria, which live on our skin and inside our body and does not cause any harm and are called good or protective bacteria. Harmful bacteria are those bacteria which cause harm by entering our body. They reproduce, engulf and kill the protective bacteria and start destroying the host cells by releasing toxins. Diseases like cholera, tuberculosis are few examples of infections caused by bacteria.


They are a group of the eukaryotic living organisms and are the parasites that are thread-like. Fungi are the single cellular organisms like yeast and multicellular organism like mushrooms. These fungi are unable to synthesize their food and feed on dead and other organic material in which they live in the so-called Parasites. They reproduce both by sexual and asexual means. Few ones are harmful as they cause fungal infections like ringworm and certain ones are beneficial as they are used in certain industries to obtain certain antibiotics medicines like penicillin and food products like yeast in mainly used in all baking industries and also in beer and wine industries. They also play a vital role in the ecosystem by converting dead plants and animals to more useful form.


They are non-cellular microorganisms composed of protein, nucleic acids, and lipids. They are measured in nanometers with size ranging from 20 nanometers to 250 nanometers and could only be seen with an electron microscope. The term virus is derived from the Latin word meaning poison. They contain the core of nucleotides surrounded by a protein coat which could invade living cells. Viruses are considered as both living and nonliving organisms. They are active inside host cells and reproduce inside them by infecting living cells

They are present in food that we eat, air which we breathe and enter our body by touching any surface that is contaminated and by consumption of contaminated foods or water. They could also enter into our body through the cuts, injuries, and scratches on the skin. Diseases like Polio, measles are a few examples of infections caused by a virus.

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Citric acid can be produced from: