How did Fleming create penicillin?

Answer 1

He discovered it by accident in 1928 while he was investigating the properties of staphylococci. He had left a number of staphylococci cultures on a bench when he went on holiday and ond return found (famously remarking:"That's funny!") that a fungus had grown in the meantime on the cultures that had killed the surrounding staphylococci. The fungus was discovered to be of the Penicillium family. After further testing and development, he managed to isolate the substance that had the bacteria-killing effect and called it penicillin.

Fleming however never succeeded over the following years to produce it in quantity. It was only in 1943 - after Fleming had given up trying - that Howard Florey and Ernst Boris Chain at the Radcliffe Infirmary in Oxford managed to mass-produce it and made it the life-saver it was to become.