The Penicillium mold (fungus) was accidentally discovered by Alexander Fleming in his laboratory in 1928. The fungus produced pencillin which blocked the growth of Staphylococcus (a bacteria). Penicillium is important for the production of penicillin, an antibiotic.
Penicillin took a long time to come on the market. It was made available by the end of the Second World War (1945), and helped to save soldiers on the battle field from influenza (flu), who would otherwise die. Thus, penicillin was hailed as a saviour of the soldiers involved in the great war. More soldiers were returning after the war due to penicillin. Even postal boxes had penicillin posters draped them, with the words, 'Penicillin cures gonorrhea in 4 hours'.
While the initial green fungus (Penicillium notatum) was grown in petri dishes, the fungus grows well on orange skin. It also grows well on orange skin kept in the fridge and on stale bread. However, higher yields of penicillin comes from Penicillium chrysogenum grown on the flesh of cantaloupe (a fruit like a melon, with orange flesh).
Penicillin allergy is uncommon but people who have severe allergy to penicillin have severe itch after trying oral penicillin or died after being injected with penicillin. Doctors will always ask parents or patients before prescribing or administering penicillin. You should know whether you are allergic to penicillin or otherwise.
Commercial penicillin is produced by fermentation, which is done in batches using cultured media from microbial sources (not animal sources). Corn steep liquor is mixed with glucose (as carbon source) and first sterilised in tanks. The fungus is added to the fermentation tanks and produces penicillin as a natural secondary product (metabolite). The fungus is then separated from the penicillin (in the fermentation broth). The penicillin is then purified for use as medicine. The fungus is recycled to produce another batch of penicillin.
There was one poster which said, 'Try Penicillin. Made from mold, you can get this drug from your doctor or prepare it yourself'. It is alright to try and see Penicillium growth on orange skin and/or bread at home. However, care has to be taken not to contaminate other food kept at home or stored in the fridge. Care has also got to be taken not to breathe in the spores released from the fungus. If you can smell the fungus, the spores are already inside you! Keep your distance or use a face mask. Take pictures and destroy the fungus by burning it outside your home. Take precaution when you use fire.
External links:
https://botit.botany.wisc.edu/toms_fungi/nov2003.html
https://labmonk.com/fermentation-process-of-antibiotics
https://www.nlm.nih.gov/exhibition/fromdnatobeer/exhibition-interactive/illustrations/penicillin-alternative.html
https://www.slideshare.net/seetaram443/penicillins-53561419
https://www.slideshare.net/banuman35/penicillins-by-dr-panchumarthy-ravisankar-mpharm-phd
