Have you ever stopped to think about the effect clothes dye has on the environment? Most people have not but we all complain when the colours on our favourite outfits start to fade.
For more than 60 years the chemical industry has been producing dyes using concentrated acids and nitrates.
However, up to 15 percent of these harmful colorants are released into the environment when colours run in the wash and so to combat this, Biochemist Estelle Enaud has been studying ways we can use fungi as an alternative, natural colorant.
At the Catholic University of Louvain in Belgium, she works within the EU-funded research project SOPHIED, testing the fungi’s enzymes to create “eco dyes”.
“Enzymes are proteins produced by the fungus. They’re nano catalysts. This means they’re tiny particles that are capable of accelerating reactions,” she said.
To extract these nano catalysts the scientists cut the fungi into small pieces and put them into a liquid that contains nutrients. By keeping the specimen in a warm chamber, the fungi grows and releases the desired nano-sized proteins. When the fluid and the proteins are added to an acidic solution, the transparent liquid turns into colourful dyes without the need for any dangerous chemical reactions.
The small enzymes help to trigger a safe chemical reaction between two different ingredients. Then, the solution turns red, yellow or purple, depending on the components.
“You’d expect us to be able to make all the colours of the rainbow. But for now we’ve only managed yellow, orange, red, a lot of brown, and a little green … but not blue,” she adds.
The new dyes are applied directly to the textiles meaning extra chemicals that can pollute water are not needed. The first tests have shown the dyes are resistant to washing and mechanical abrasion. However, in the sunlight, the eco-dyes do fade and so, the research continues to perfect the process and make a resistant but colourful eco-dye.