Antibiotics are substances produced by microorganisms that can destroy other microorganisms, or inhibit their growth. Most antibiotics are made by bacteria (such as “Streptomyces”), and a few are made by fungi such as Penicillium.
Antibiotics were first discovered in 1928 by Alexander Fleming; however they were not commercially produced until 1941.
One thing to take note is that Antibiotics are either; * Biocidal (they kill other organisms.) * Biostatic (they prevent the multiplication and growth of micro-organisms.)
As said before, Alexander Fleming discovered antibiotics in 1928. On the morning of September 3rd, Fleming was sorting through some glass plates that had recently been covered with bacteria as part of his research. Fleming noticed that on one of the plates, some mould had grown, and around this mould, no bacteria had grown. He concluded that there was a substance in the mould that was killing of the bacteria.
The mould that had grown was called Penicillium Notatum.
Fleming continued research on this mould, and found that it could be given to animals to kill bacteria, without any side effects.
It was 10 years later, when two scientists called Howard Florey and Ernst Chain isolated the bacteria-killing substance in the mould – Penicillin.
Antibiotics generally work in two ways, either by preventing bacteria from making normal cell walls, or by interfering with the internal biochemistry of the bacteria.
More particularly, they:- * Prevent Cell Wall Synthesis. – The cell walls of bacteria are essential to stop the cells from bursting when water enters them. Antibiotics inhibit the synthesis and assembly of the cell walls. This causes them to become weak, and they burst (killing the bacteria). Penicillin works in this way. * Interfering With Nucleic Acid Synthesis – This is when the antibiotic inhibits synthesis of DNA or changes the formation of messenger RNA, which makes the bacteria unable to multiply. * Interfering With Protein Synthesis – This is when antibiotics bind to the ribosomes of bacteria. The antibiotics prevent all protein synthesis, stopping the bacterial cells from multiplying. * Damaging Cell Membranes – Antibiotics can distort the lipid bilayer of the cell surface membrane of the fungi. The damaged cell membrane allows the