Moulds are a group of fungi. They’re very important in the process of decay, and they also create the ‘veins’ in blue cheeses like Stilton. But there are a few that do something far more important than giving us something tasty to put on biscuits…
In 1928 Professor Alexander Fleming went on holiday (something you could still do, back then…). He was working on the bacteria that cause sore throats, and he left some dishes with the bacteria growing in them in his notoriously untidy lab when he left.
When he returned, he noticed that one dish had mould growing in it and that the bacteria nearest it had disappeared. Intrigued, he grew the mould, tested it and found it produced a chemical that could kill many types of bacteria. The mould was called Penicillium notatum so he named the chemical penicillin. He discovered it couldn’t be stored for long, and that it didn’t harm mice if they were given a dose.
…But it was so difficult to extract and purify that scientists lost interest in penicillin! You’ll have to come back tomorrow to find out what happened next