(Science: person) this native of Scotland studied medicine at St. Mary's hospital medical school in london, where he won almost every prize and scholarship prize available. He graduated with honors in 1908 and 20 years later became professor of bacteriology at his alma mater.
During world war i, he devoted his interest to problems of infection and developed an antiseptic proteolytic substance, lysozyme (muramidase). He managed a vaccine for acne, and developed a miniature technique for the Wassermann (syphilis) reaction. Although the Belgians, Gratin and path, in 1925 reported a mould, Streptothrix, which inhibited the growth of staphylococcus, alexander fleming was the first to prove such in 1928.
Fleming found the mould penicillium notatum, listed the organisms sensitive to it, emphasised that it was not toxic to leukocytes, and used it on surface wounds 12 years before it became commercially available.
Fleming's description of his discovery is interesting - I opened a culture plate of staphylococci and something fell from the air onto the plate. Later i saw lysis of the staphylococci colony. Instead of casting out the contaminated culture with appropriate language, i made some investigations. My lab was dingy and 4c4 dim coloured. If this had been an American lab, this could never have been discovered.