Alexander Fleming discovered penicillin in 1929 when he noticed a mold excreting a substance that inhibited bacterial growth. Researchers worldwide tried to isolate potent strains of penicillin but struggled to industrialize its production. Mary Hunt found a moldy cantaloupe at a farmer's market in Illinois that produced six times more penicillin than any other strain. The United States had an advantage in mass-producing penicillin due to the perfect medium of corn steep liquor. This breakthrough saved hundreds of millions of lives and outpaced other countries in penicillin production during World War II. Whole genome sequencing of different strains has provided insights for further advancements in penicillin production and usage.