Know your phage

Is a bacteriophage living or non-living entity?

Bacteriophage on the surface of bacteria UK innovate
Bacteriophage on the surface of bacteria ready to inject its DNA content


Phages, like other viruses, have a complex life cycle that causes them to be classified as non-living, despite the fact that they exhibit some of the characteristics of a living entity. Viruses and phages are not considered complete living organisms because they cannot carry out biological processes without the assistance of another organism and its cellular machinery. Proteins, nucleic acids, lipids, and carbohydrates are examples of complex molecules. They can’t do anything on their own until they enter a living cell ( bacterial cell in case of phage). Viruses cannot multiply in the absence of cells. That is why they are referred to as non-living things.

List of characteristics of bacteriophage as a living thing and non-living thing

Living characteristics of bacteriophagesNon-living characteristics of Bacteriophages
 Capable of multiplying inside a host cell (bacteria)An obligatory intracellular parasite.Cannot multiply extracellularly, i.e., Outside the cell.
Capable of infecting another cell (bacteria).Metabolic activity is absent.
Possesses nucleic acid (either DNA or RNA), proteins (Capsid), and Enzymes for replication.Protoplasm is absent.
Can mutate.Crystallization of viruses is possible.
Table showing characteristics of bacteriophages as living and non-living entities
A group of bacteriophages injects their DNA into a bacterium Courtesy Image from Eye of Science  Science Source
A group of bacteriophages injects their DNA into a bacterium Courtesy Image from Eye of Science Science Source

Viruses are the most primitive non-cytoplasmic and cellular infectious agents. D.J. Iwanowski, a Russian botanist, discovered the virus in an infected tobacco plant in 1892. The term “virus,” on the other hand, was coined by M.W. Beijerink (1898). Then, in 1935, W.M. Stanley, an American chemist, isolated the pure crystal of Tobacco Mosaic Viruses (TMV) and concluded that viruses are made of nucleoproteins.

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About the Author

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Raphael Hans Lwesya
Hello and welcome, My name is Raphael Hans Lwesya, and I am the founder of The Phage. I am currently pursuing a PhD focused on the human gut phageome and its role in healthy ageing and cognitive decline. I hold a Bachelor’s degree in Biomedical Laboratory Technology and a Master’s degree in Molecular Biology. I have a strong interest in bacteriophage research and science communication, and I am passionate about making complex scientific ideas accessible. Through The Phage, I aim to present current phage-related research in a clear, accurate, and engaging way. Thank you for visiting The Phage. If you have any questions, suggestions, or would like to get in touch, please feel free to leave a comment or contact me at raphael.hans@thephage.xyz.

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