Friendly fungi

by Ranjini Murali

 

Last week, we told you the story of a deadly kind of fungi that took over the brain of an ant. But not all fungi are dangerous. There are some that are immensely useful.

Scientist Alexander Fleming, whose birthday falls this month (August 6) is celebrated for his role in helping the human race fight disease. But the real warrior behind our battle against illnesses such as pneumonia and meningitis is a kind of fungi. It’s just that Fleming accidentally discovered this useful fungi. Here is the story:

The year is 1928. People are dying of infections such as scarlet fever, meningitis, syphilis and gangrene. The most the doctors can do for them is pray and wait. In a dingy basement laboratory in London, sits Fleming. He is researching a group of bacteria called Staphylococci which are responsible for causing many fatal infections. Looking at his multiple petridishes in despair, he decides he needs a short vacation. ‘I can come back and tackle this with a fresh mind’, he thinks to himself.

A few days later, Fleming enters his lab feeling optimistic. He pulls out his multiple petridishes of the bacteria from dusty cupboards. He notices that one of his cultures has been contaminated with a fungus.

Sighing, he places that petridish apart from the others, meaning to dispose of it properly later. Just as he places the petridish on the table he notices something very odd. He notices that the colonies of Staphylococci immediately surrounding the fungus have died but the colonies further away are thriving.

Intrigued, he isolates the fungal colony and researches it further. He discovers that the fungus belongs to a genus called Penicillium . It produces a substance capable of destroying many bacteria which cause fatal disease such as meningitis, syphilis, scarlet fever and pneumonia. Hardly daring to believe what he has stumbled upon, he calls this substance Penicillin.

Little did he know that this discovery was to change the face of modern medicine.

Mighty warrior

That’s how a life-saving drug was derived from an ordinary fungal mould – Penicillium. Fleming is commonly attributed with the discovery of penicillin, one of the most powerful antibiotics in the world. An antibiotic is a chemical substance produced by a micro-organism, capable of killing other micro-organisms.

Although Fleming guessed at the potential uses that penicillin could have, he had difficulty isolating it and producing it on a large scale. Isolating and concentrating penicillin was later done by Ernst Boris Chain and Edward Abraham in 1940. Following this, Norman Heatley discovered how to produce it on a large scale. New research into the antibiotic properties of several other fungi followed. Cephalosporin from the fungal genus Acremonium , lovastatin from Aspergillus and griseofulvin also from Penicilliumare some examples of antibiotics used today to treat infections.

However, as the Spiderman movie says, “With great power, comes great responsibility”. While these antibiotics have great power to save us, overuse or misuse of these can be very dangerous. Bacteria can become resistant to these antibiotics and can continue to cause infection. This is called antibiotic resistance and once this happens, the infection will be much harder to treat.

Other helpers

Although antibiotics are a part of modern medicine, the infection-fighting properties of several fungi species have been recognized since ancient times. In 1991, a 5,000 year old corpse was exposed near the Austrian/Italian border when a glacier melted. This corpse was remarkably well preserved and among the Iceman’s equipment were three fungal species. One of the fungal species is thought to have been useful as flint for starting a fire while the other two are thought to have medicinal properties. There are records of Greeks, Japanese and Chinese using fungi in their traditional medicine. Even today several indigenous communities around the world continue to use wild fungi for medicinal purposes.

This article appeared in the Hindu in School on 8 August 2012.