Dmitri Iwanovski was a Russian botanist, and one of the discoverer of filterable nature of viruses and the field of virology. He was one of the founders of the biomedical field called virology. In 1892, he filtered infectious extract from tobacco plants infected with mosaic disease using bacterial filters (which are sieves that excluded bacteria from samples), and found to his greatest surprise that the filtrate was still fully infectious.
It was discovered later that diseases in plants and animals was caused by some submicroscopic agents that were smaller than bacteria, and that were retained in the filtrates after passing through the bacterial filters. Dmitri’s work ushered in the field of microbiology which explained a new type of infectious agents called “viruses” – that are capable of permeating porcelain filters, something which bacteria could never do.
Dmitri’s findings were studied further by other scientists like Frederick Loefller (1852 -1915), a German bacteriologist who discovered the organism causing diphtheria (Corynebacterium diphtheriae) and the cause of foot and mouth disease (Aphthovirus); F.D Herelle (1873-1949), a French-Canadian microbiologist and F.W Twort (1877–1950), an English bacteriologist who independently discovered bacterial viruses known as “Bacteriophages”.
These scientists discovered that this agent (filterable viruses) was quite different from cellular organisms like bacteria whose structure and development are already known. But in 1935, Wendell Stanley crystallized virus and found that it is made up of protein and nucleic acids.
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