We have all heard that antibiotics are powerful medicines that fight infections and can save lives, but do you know how they work or how they are made?

Antibiotics are chemical substances that interrupt the processes responsible for building cell walls, cell reproduction or protein synthesis in microorganisms,thereby inhibiting the growth of, and even destroying, the cells. They do not fight illnesses caused by viruses such as the flu, or most colds, and can even make a viral infection worse.

There are over 10,000 antibiotic substances, with some highly specialised to fight only certain bacteria, while others are known as ‘broad-spectrum” antibiotics, which kill most bacteria, even the ones that are beneficial to us.

Antibiotics begin to work immediately upon ingestion or application, but treatment time varies from one infection to the next. Typically, treatment lasts 7-14 days, even if symptoms subside earlier. Failure to complete the full course can lead to the remaining bacteria building a resistance against the antibiotic that was used, and a failure to fully kill the infection.

Although most antibiotics occur in nature, they are not available in large quantities, therefore lab production was developed using fermentation. The organisms that produce them are grown in large fermentation vats, where they can later be refined, and the antibiotics can be extracted. The process begins with a fermentation broth: a solution of ingredients needed for rapid reproduction of the antibiotic-producing microorganisms.
This broth typically consists of:
1. A carbon source made of lactose and glucose- often molasses & soy meal
2. Nitrogen- from ammonia and salt
3. Trace elements- phosphorus, sulfur, magnesium, zinc, iron and copper

The first antibiotic, Penicillin, was found by accident in a fungus growing on a petri dish. The fungus was then grown in large amounts so the penicillin could be harvested. The first modern antibiotic, sulfanilamide, was created in 1926, but then largely distributed during the Second World War. Today, antibiotics represent a multibillion dollar industry that continues to grow each year, as they make possible many complex medical procedures that have become routine around the world. However, the overuse, and over-prescription, of certain antibiotics has led to the evolution of deadly antibiotic-resistant strains of bacteria, which is viewed as the next great health crisis.