Who discovered antibiotics Penicillin?

Chimex wrote:Who discovered antibiotics Penicillin?

Queen wrote:You must have heard about penicillin the wonder drug that cures many bacterial diseases. This drug was accidentally discovered by Sir Alexander Fleming while he was studying the growth of a certain type of bacterium. 

Below is how Fleming made his discovery.

Step 1: Fleming was studying the growth and reproduction of the bacterium Staphylococcus is dishes containing agar to which nutrients had been added.

Step 2: He observed that a mould Penicillium was also growing in some of the dishes. (The mould had got the dishes by accident) In addition, he observed a clear zone around the area where the mould grew, indicating that the bacteria growing there had died.

Step 3: What had caused the bacteria to die?

Step 4: Fleming put forward a hypothesis: the mould produced a chemical which diffused into the surrounding agar and killed the bacteria.

Step 5: To test his hypothesis he designed an experiment. He grew the mould in a liquid nutrient broth so that the chemical it produced would diffuse into the broth. He added some of this broth minus the mould to the bacteria.

Step 6: He observed that the bacteria died after broth was added.

Step 7: Was there something in the nutrient broth that caused the bacteria to die?

Step 8: To find out the answer to this question; he added some nutrient broth in which no mould had been grown to the bacteria.

Step 9: The bacteria did not die.

Step 10:  The confirmed that Fleming’s hypothesis was correct. It was tested by other scientists. The chemical was isolated and named penicillin.