What did sir Alexander Fleming discover?

Answer 1

In 1928, Fleming was working on the staphylococcibacteria - the kind that cause boils and sore throats, when, whilst he was examining some old bacterial plates that he noticed a mould had grown on one of his cultures. He saw what he believed was unusual in that some of the colonies of staphylococci that should have been growing near the mould had disappeared. Fleming thought that the mould could be making something that was capable of destroying the bacteria. He did some more experiments and found that this was indeed the case. He cultured the mould by growing it in broth. The mould was later identified as Penicillium notatum which had produced what we now call penicillin.