ABSTRACT
Alexander Fleming’s original observation in 1928 was of a fungal mould Penicillium notatum that exuded a substance that seemed to kill bacteria that were growing on nutrient agar. Fleming called the substance penicillin. This lucky observation was the first antibiotic, and the start of our ongoing war with infectious bacteria. The problem was that extracting the tiny amounts of penicillin from moulds grown on Petri dishes in the lab was time-consuming and difficult. The US and UK governments made it a priority to find a way to mass produce penicillin, and a worldwide search was found for a source of mould that would yield the best-quality penicillin. Research on fermentation of corn steep liquor, together with the new process of deep-tank fermentation, allowed the cantaloupe penicillin to go into large-scale production. Bacteria adapt rapidly so that mutations can arise that alter the receptor sites, making it impossible for penicillin to bind to them.
